Playing against stronger players

1) They may find something you're not aware of. We never know what we actually don't know.
2) Even if you know your weaknesses, you may not know how to exploit them effectively. Stronger player can show you that. What is more important, you may learn that tactics to use by yourself against different players with the same weak sides!
3) Many people are aware of their weaknesses but do nothing to fix them because opponents at their level cannot exploit them well. If you play regularly with someone who does this regularly, you will be better motivated to work on your weak sides.
4) Often people get motivated when they regularly face someone who is stronger, but at the reachable level. Playing closer games or winning can become a challenge that gives you more motivation to improve.

Illia,please,don't you have any idea how can I solve the situation when no one except PingSkills is willing to help me with looking for my weaknesses and their reasons are "You cannot utilise the tactics that I am able to teach because it would require you to play without long pips" or "it is a secret" or "I cannot advise a defender" etc. ?

A few things that happen to me when playing stronger players:

1) My usual tactics don't seem to work any longer. They pick my serves with which I confuse weaker players. They block my topspins which weaker players push out.

2) Their serves are better and they put me under pressure, while I'm used to put the weaker players under pressure.

So, I need to be more ready for 3rd ball because their returns will be good. And I need to concentrate much more on my own returns. Also, I will have to change tactics faster and more often, so I'll need to think more about variation of spin or placement, and figuring out what exactly isn't working.

DK, you can't rely on other players to fix your own game. You need to discover your weaknesses yourself and talk about them with a coach (live or online).

Last match, I was having lots of trouble with half long backspin serves which looked like tomahawk side spin serves. I'm going to ask some of my peers to throw serves like those to my backhand and replay that part of the match situation which I was struggling with.

Coach always tells me that I should attack it or if it is short then make a short return and attack next ball.
Maybe he hates my hard-headed attempts to play the ball long but in a way that is hardest to return fast.

He always says that my only weakness is that I do not attack everything with both wings and of course the overall level.
He says that my skills that I should use (loops,smashes,flicks) are on the good level and that I just need to be more agressive and give up any backspin balls.

He even said that my loop can be occassionally on par with his own loop.
I do not really believe him,because his loops are rarely blocked at the level where he plays if plays for our team,mine always.
(he plays on much lower level than he is,because we do not have a team in so high league and also he wants to raise our self-conscience by standing by us)

The only ones who would objectively advise me are Alois and Jeff,but I think that I am bothering them a bit.
And after that I am not a premium member so I cannot show them my full matches.

About my weaknesses...I could probably find them.
But it is  hard to overcome them if some of them are caused by my by-glasses-irrepairable sight

Provoke your opponent to play some complex shots that will help to learn something new.

In my case they will not.
They will force me into smashing or bomb me off.

I asked a similar question: What to learn from playing the best players?

DK its good to smash the ball as it will help you to increase the ball speed and power of your stroke.

It will also help to read your opponent's trick and try them.

Of course I usually smash it.
But I am weak and they use my smashes to create a power for their own attack.