Some Support gems do not raise the damage

Some support gems that add damage in certain areas are not shown or affected when looking at stats. Plus since not doing the proper amount of damage also has an insta death in spots were i die from the same enemy 10 times before killed. My resistance is above 50 and insta death? Come on. Theres something tragically wrong here and its a bit of everything. An enemy standing in a certain spot cannot take damage. Some spots on the map you get stuck even though nothing is there.. Game needs a big fix

Maybe you are linking the wrong support gem.

Lv53 should not be worried much, usually 4 links can pass everything smoothly.

I can't read your character as you have set it private, make it public so we can look into your issue.

You can also visit poe ninja to see what majority is doing that similar to your build.

The most straight forward indication, whether a support gem affects a skill is a little added icon in the skills picture.

But it is true in general, that damage numbers a one parameter often cannot express all the benefits given, cause alot other circumstances take effect aswell.

As for your other concerns it is hard to tell from the outside. I had trouble with some expedition encounters not taking damage. But generally speaking this game is designed to kill the players. You are not supposed to survive everything unlike in other games. And it takes alot preparation and knowledge to progress further and further. Your resistances, which you mentioned, might not even have taken effect, cause physical and chaos damage exist too. And 50% resistances are low, cause the damage reduction/intake kind of functions exponentially, not gradually. So having 50% instead of 75% easily doubles the intake, somewhat like that.