Q:

What are the main warning signs in a Buddhist centre?

I have been to different temples/centers/monasteries from different schools, most of them I would return regularly, but in a few I found things that didn't agree with some personal views. I must say 100% of the time I found people with nothing but good intentions, but not always I agreed with the methodology, practices or some core believes, for example: Having a "cult style".
That said, I would like to ask: What are the main "warning signs" (if any) we should look for when going to a temple for the first time? (I'm not talking about a simple visit, but Dhamma talks, classes and meditation).
This question aims to help beginners, it is very hard to identify "unusual practices" when a person is just starting with Buddhism and have no idea what is Vinaya or the Suttas for example.

A:

Best is to do some reading of the main Suttas, such as: Anapanasati Sutta, Maha Satipatthana Sutta and see if what the center in question teaches corresponds with the Suttas.
Also see if the operations / techniques adhere to this:

Should ideally be run by donations and not by charging a fee
Should not be cultish
Should allow free thought and inquiry 
Should not have practices which harm oneself or make oneself agitated or do the same for others

The last point you can only know when you have practiced the techniques taught at the place and found out you are are at peace and also cordial with others. Now if you do find a lack of peace and cordiality, it may be there is something wrong with how or what you practice. However, you should then take care -- and it is easy to misjudge this -- that you are indeed following their instructions. If you do that, and rule out the possibility that you haven't followed their instructions (in which case, maybe you're just doing your own thing and that is the problem), then there is a good chance there is something wrong with what you have been taught at the particular center.
Sometimes certain traditions may not encourage practices outside the tradition (including reading). In that case you have to look at the motivation behind it. Is it trying to have a grip or hold over the person? Or is it concern that undesired results may be brought about by mixing different techniques? Or is it concern about not being able to handle dangerous results of an unfamiliar technique? Many traditions are geared towards preserving the techniques exactly as handed down through generations and due to this, variation may hamper the results/benefits. This is why you have to be very careful and try to look at it without prejudice.

A:

I think this is a very important question, but I can't see any way that a beginner who is unfamiliar with the Dharma can figure it out without essentially moving at least a little off the beginner's position. There's really no way to "bootstrap" yourself into trusting teachers without doing some upfront work yourself. So the main advice I'd give on that front is, go study the Dharma! 
But perhaps there are some general rules of thumb that could also be useful. For example, to begin with perhaps a newbie should stick with the more established traditions: Theravada, Zen, mainline Tibetan, etc. That would necessarily exclude things like Soka Gakkai International (for example), but it's not at all arguing that SGI etc are bad. Rather it's simply to say that until someone finds their feet and understands what all the styles of Buddhism have in common, it's probably best to stick with more established styles, and then as one comes to understand things decide if moving to a newer or less well known approach is right for the person concerned.
Another general principle is to watch out for the "cult style" as the OP mentioned. Some good pointers in that direction are to be found around the net -- here for example. So if they're demanding unreasonable amounts of money, or seem to be highly dependent on the personality of the teacher, it's worth putting those on the list of "reasons for possible concern".
A third point is perhaps more controversial, but I'll offer it anyway being based on my own experience. I confess that to some extent I am a newbie in this situation. I have studied quite a bit, and have established a basic meditation practice, but I still haven't yet decided on a teacher, tradition, and so on. I consider that to be a very important part of my practice right now. And one of my considerations is to look at the life of the tradition's founder and those of its major figures. For that reason, I find myself a bit hesitant to engage with, for example, Shambhala. I still find myself trading off the huge contributions they have made, in terms of publication and teaching, and also some of their ideas, with the lifestyles and actions of the founder Chogyam Trungpa and his successor Ösel Tendzin. This is a very personal thing, and as I say I'm not rejecting Shambhala outright, but I suggest that observing the correspondence between the actions and teachings of major figures in the organization is a useful test. 

A:

Health warning - this is a answer based on particular personal experience but I hope it's got some value in answering the question
I practice with a sangha (Triratna) which has been accused of cultish behaviour in the past. There is a decent sized article on wikipedia about these allegations. But to summarise the concerns have been around lack of proper lineage, sexual misconduct from the founder and particular centres developing a cult of personality leading to exploitation of newer members. This sounds dreadful and alarming particularly as I write it down. In fact they have changed their name since then from FWBO to Triratna. They never publicly admitted to this but I suspect that part of the reason was to put some distance between the organisations controversial past and the more positive present. So why on earth do I practice with them?
I think that you can only judge a centre through contact with your local group. For instance these are the questions that I have asked myself

Does the group seem welcoming to newcomers?  
Are I comfortable with the practices?  
What are the people who have been around for a while like? Do they seem like regular sane people?  
Am I comfortable with how money is been asked for? I like beginners course
to be just chargeable at a reasonable rate just as if I am signing up
for a night class. It might be different to for you.  
Is the  centre supportive of people with families. 
Is there events that welcome non-Buddhists  
Is there a well structured supportive program for beginners
Can the centre cope with descenting opinions and views from alternative teachers.
Is there reference or study of traditional canonical texts e.g. Pali
Canon, White Lotus Sutra etc...

As far as Buddhist practice goes in my humble opinion so long as they are teaching the 4 noble truths and the eightfold path then I would say this is Buddhist enough to engage with them. If further down the line they seem to be veering off then you can always try elsewhere.
This is an interesting and challenging question for me because I have chosen to spend 7 years practicing with a Buddhist group that has has a controversial past (although it has been received a lot more positively in the last 30 years or so). 
If I can end with why I chose to go there in the first place

I had a personal recommendation from someone I trusted  
The centre was near to where I worked 
The didn't seem to do a lot of chanting/ritual which I couldn't get on with at the time

Are they great reasons to commit to a particular centre? Probably not - maybe I just lucked out because I've had a very postive 7 years.

