user17928: Should we care about what others think? If so, to what level? (Most of the time, those thoughts creates suffering).

user295: Tryin to project one's self-image into the minds of others is a source of suffering1. So one should look inwardly and constraint oneself with the precepts and also develop the Brahavihara and be benevolent. This protects others also oneself. Beyond this worrying about what others think will create misery as this is not in one's control and one's ego is expanding from the spere of "me" to "dear ones" and "others" (also see link below). The misery will be more closer you are to the person in question.

1 This is highlighted in this example: Vipassana | S.N. Goenka | The Ego - "The teacher and his 5 students"

user13694: Maybe if it's people that cares about you and your spiritual progress. Good friendship with good advices/criticism is a treasure to be protected.
In the Dhammapada, we see that:

Should one a man of wisdom meet
  who points out faults and gives reproof,
  who lays a hidden treasure bare,
  with such a sage should one consort.
  Consorting so is one enriched
  and never in decline.
Let him exhort, let him instruct,
  and check one from abasement.
  Dear indeed is he to the true,
  not dear is he to the false.

Kind regards!

user12753: Yes, as long as this would boost the desire to abandon what is unwholesome and undertake what is wholesome.

these two bright qualities guard the world. Which two? Shame &
compunction. If these two bright qualities did not guard the world,
there would be no recognition of ‘mother’ here, no recognition of
‘mother’s sister,’ ‘uncle’s wife,’ ‘teacher’s wife,’ or ‘wives of
those who deserve respect.’ The world would be immersed in
promiscuity, like rams with goats, roosters with pigs, or dogs with
jackals.
https://www.dhammatalks.org/suttas/AN/AN2_9.html

.

Now if I, having gone forth, were to think thoughts of sensuality,
thoughts of ill will, or thoughts of harmfulness: Great is the
community of this cosmos, and in the great community of this cosmos
there are contemplatives & brahmans endowed with psychic power,
clairvoyant, skilled (in reading) the minds of others. They can see
even from afar. Even up close, they are invisible. With their
awareness they know the minds of others. They would know this of me:
“Look, my friends, at this clansman who—though he has in good faith
gone forth from the home life into homelessness—remains overcome with
evil, unskillful mental qualities.” There are also devas endowed with
psychic power, clairvoyant, skilled (in reading) the minds of others.
They can see even from afar. Even up close, they are invisible. With
their awareness they know the minds of others. They would know this of
me: “Look, my friends, at this clansman who—though he has in good
faith gone forth from the home life into homelessness—remains overcome with  evil, unskillful mental qualities.”’ So he reflects on this: ‘My persistence will be aroused & not lax; my mindfulness established & not confused; my body calm & not aroused; my mind centered & unified.’
https://www.dhammatalks.org/suttas/AN/AN3_40.html


17928: <p>Should we care about what others think? If so, to what level? (Most of the time, those thoughts creates suffering).</p>
 295: <p>Tryin to project one's self-image into the minds of others is a source of suffering<sup>1</sup>. So one should look inwardly and constraint oneself with the precepts and also develop the Brahavihara and be benevolent. This protects others also oneself. Beyond this worrying about what others think will create misery as this is not in one's control and one's ego is expanding from the spere of "me" to "dear ones" and "others" (also see link below). The misery will be more closer you are to the person in question.</p>

<hr>

<p><sup>1</sup> This is highlighted in this example: <a href="https://www.youtube.com/watch?v=Al6avEKEpJ0" rel="nofollow noreferrer">Vipassana | S.N. Goenka | The Ego - "The teacher and his 5 students"</a></p>
 13694: <p>Maybe if it's people that cares about you and your spiritual progress. Good friendship with good advices/criticism is a treasure to be protected.</p>

<p>In the <a href="http://www.buddhanet.net/dhammapada/d_wise.htm" rel="nofollow noreferrer">Dhammapada</a>, we see that:</p>

<blockquote>
  <p>Should one a man of wisdom meet
  who points out faults and gives reproof,
  who lays a hidden treasure bare,
  with such a sage should one consort.
  Consorting so is one enriched
  and never in decline.</p>
  
  <p>Let him exhort, let him instruct,
  and check one from abasement.
  Dear indeed is he to the true,
  not dear is he to the false.</p>
</blockquote>

<p>Kind regards!</p>
 12753: <p>Yes, as long as this would boost the desire to abandon what is unwholesome and undertake what is wholesome.</p>
<blockquote>
<p>these two bright qualities guard the world. Which two? Shame &amp;
compunction. If these two bright qualities did not guard the world,
there would be no recognition of ‘mother’ here, no recognition of
‘mother’s sister,’ ‘uncle’s wife,’ ‘teacher’s wife,’ or ‘wives of
those who deserve respect.’ The world would be immersed in
promiscuity, like rams with goats, roosters with pigs, or dogs with
jackals.</p>
<p><a href="https://www.dhammatalks.org/suttas/AN/AN2_9.html" rel="nofollow noreferrer">https://www.dhammatalks.org/suttas/AN/AN2_9.html</a></p>
</blockquote>
<p>.</p>
<blockquote>
<p>Now if I, having gone forth, were to think thoughts of sensuality,
thoughts of ill will, or thoughts of harmfulness: Great is the
community of this cosmos, and in the great community of this cosmos
there are contemplatives &amp; brahmans endowed with psychic power,
clairvoyant, skilled (in reading) the minds of others. They can see
even from afar. Even up close, they are invisible. With their
awareness they know the minds of others. They would know this of me:
“Look, my friends, at this clansman who—though he has in good faith
gone forth from the home life into homelessness—remains overcome with
evil, unskillful mental qualities.” There are also devas endowed with
psychic power, clairvoyant, skilled (in reading) the minds of others.
They can see even from afar. Even up close, they are invisible. With
their awareness they know the minds of others. They would know this of
me: “Look, my friends, at this clansman who—though he has in good
faith gone forth from the home life into homelessness—remains overcome with  evil, unskillful mental qualities.”’ So he reflects on this: ‘My persistence will be aroused &amp; not lax; my mindfulness established &amp; not confused; my body calm &amp; not aroused; my mind centered &amp; unified.’</p>
<p><a href="https://www.dhammatalks.org/suttas/AN/AN3_40.html" rel="nofollow noreferrer">https://www.dhammatalks.org/suttas/AN/AN3_40.html</a></p>
</blockquote>
