Flexibility in my opinion is extremely underrated. I think being flexible can be one of the greatest tools in climbing.
I myself am not flexible at all, but my friends are, and the difference between how we climb is so noticeable. Moves that are so difficult for me are just easy to them.
You dont have to be flexible to climb, but, it would make a huge difference if you were.
It can equal stronger climbing, but not necessarily better climbing.
The problem with being very strong is that you start to neglect technique, because if you can just power yourself to the next hold or through the move, why would you do it in a more technical way? Even if you try to be more technical, it can be very hard to get rid of the habit of powering through moves. This is something many climbers struggle with, including myself.
On the other hand, if you are a technical climber, but are weak in terms of physical strength, training your forearms can help quite a lot by balancing you out a little bit. So you would still have the technique that you have developed until now, and you would also just be physically stronger.
So I would say that it just depends on your current situation. Are you more technical, or are you more powerful?
This is a very general question. Is it for bouldering? Sport climbing?
There is too much missing information in the question to be able to actually answer it accurately, but, in any case, it would most likely depend on your experience, technique, strength, and how determined you are.
I think its just a matter of preference. I personally order very cheap chalk blocks online and just break them up in my chalk bag.
Not so much that it will spill out, and not so little that you have to scrape the sides for it.
I tend to have 1-2 broken down chalk blocks in my chalk bucket. But this also depends on the size of your chalk bag.
What really helped me get better at sit starts was climbing on a moon board, and either finding boulders that have sit starts, or building new boulders with sit starts.
I was pretty bad at sit starts since they are very compressed for me, something I am fairly weak at. But after climbing for about a month almost only on the moon board, I really saw the improvement, and it was very noticeable.
I still work quite often on the moon board, and I can really see the difference from before and after. I try to do the most disgusting sit starts possible on the moon board, and I can do all of the sit starts on the regular route setting walls.
The moon board in my gym is a 30 degree angle I believe. If you don't have a moon board, I think you can probably do the same on any other system board.
Try to find the next best thing that you do have. Do you have a spray wall? If not, do you have an overhanging wall that you can make up boulders on using the existing holds?
Otherwise, I would just make up boulders anywhere in the gym and try to make them system-board-like.
There isn't really a "supposed to" or not when it comes to socks. You either prefer them or you don't.
Some wear them due to hygiene, some due to shoe sizing, and for some it's just comfortable.
Undoubtedly though, the majority of climbers do not wear socks with climbing shoes.