Q:

と聞いて in this sentence

山に登るのは大変そうだから、本当は行きたくなかった。
Climbing mountain seems difficult so truthfully, i didn't want to go...
The second sentence is the one i need help with... I wasn't sure if i get it right... 
でも ロープウェイを 使って登れば、大丈夫だと聞いて、行くことにした。
Rough literal translation that I grasp: But,if using ropeway to climb, i heard it is okay,then i decided to go.
So I somewhat understand it as: "But i heard that it's okay to use ropeway to go up so i decided to go in the end.
I don't quite understand 大丈夫だと聞いて part. I think the と is the quotative one so it might means "It's okay" i heard . But if that's the case, why V-て instead of V-た... Like what we do with と 言った.

A:

You are right that と is quotative. The verb is 聞いて instead of 聞いた because the て-form here is being used to chain a sequence of events together: the speaker hears that it is okay to climb using the ropeway, and then decides to go. Using 聞いた instead would be ungrammatical, since it is not the final verb in the clause.
The same thing could happen with 言う. For example:

彼は「さよなら」と言って出た。- He said "goodbye" and left.

Since it's followed by another action, 出る, the verb いう must be in its て-form.

A:

To add to that answer, I just wanted to point out a few key points: 

In the first sentence, it is not "i don't want to go," but "I didn't want to go."  Don't miss the past tense in 行きたくなかった
So now look at the second sentence and it also ends in past tense (行くことにした), so the resulting meaning is not "so I decided to go in the end," but "so I went in the end."

Note: see comments, "decided to go" turns out to be correct in context.

Also wanted to point out that ロープウェイ (you misspelled it) refers to what we would call a gondola (or similar term) in English.  Specifically, this refers to the larger gondolas, whereas small 6-8 person gondolas can be called ゴンドラ.

For a better idea of what ロープウェイ refers to, here is a google image search:
Google Images: ロープウェイ
I point this out so that the translation becomes more easy to understand.  If you use the "ropeway" then you will be riding up most of the mountain, you may do a little hiking to get to the ropeway entrance and a bit of hiking to the peak after you get off the ropeway.  Another common option is to ride up and hike down.

Final point.  While the literal translation of 山登り is "mountain climbing" in English, you should keep in mind that what most Japanese people mean when they say 山登り is what we would call "hiking" in English. This is because the mountains in Japan are not very tall.  Even Mt. Fuji, the tallest mountain in Japan, does not require oxygen to reach the top, you do not need any special climbing equipment, and you do not need to use your hands and feet to "climb" up the side of the mountain.  I've had a lot of personal experience doing 山登り all across Japan (including Fuji), and it is always a bit difficult to talk to my friends and family in the US about it because I start out by saying that I did a lot of "mountain climbing" in Japan, which gives them the idea that I am an experienced rock climber, which is (unfortunately) not the case.  

You may not need to change your translation of 山登る, as long as you (and your target audience) understand what the intended meaning is.
Hope that helps!  

