what is the best thing to do if you have about 10 times de BB while in a tourney?
what hands should I play and how?
do i absolutely need to catch a hand and double up?
do i have enough chips to wait for the big one?

if you get to 20 times the BB, should you open with hand like KJ and KQ, what about small pairs?

There are many other factors to consider when deciding which hands to play.
For example, your position, your opponents style, your opponents chips, your table image, how far away you are from the money, etc. These factors will determine which hands you can raise with.
With 10xBB, I like to open for 3x-4xBB raise. 2 times the blind is too small, but with this amount of I am reraised, I'm comfortable with letting the hand go, and still have 7xBB in my stack.
You have enough chips to wait for a pretty decent hand, but I would usually push PF with 88 or better.
Even with 20x the BB, I usually limp with small pairs, unless its shorthanded, or I'm looking to steal from LP or the button.
Again, with KJ and KQ, it depends on your image and the situation. Sometimes you can raise, sometimes you can't.
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Bubbler Pipe

With 10BB I will RARELY see a flop, its the point where I'm pushing or folding preflop. There are some situations where you can 3bb or limp but its rare. Generally I'm waiting for 77-99+ depending on position and the table. If its a SnG play position really well and you can open on some weaker hands to build to 15-20bbs where you have a much better shot.

The best way to learn is to post specific hands and let people comment on them.

It would take a book chapter to properly discuss this.

At also depends on your goal, or you looking to gamble to double up? Do you want to have the best of it?

I like to avoid really weak aces like A4, you are usually only about a 53% favorite at best. But you usually arent much worse than a 2:1 dog either.

Give us some scenarios (like hand histories of your situation you are probably refering too) and we can attack/dissect them for your improvement.....

There's a good chart on opening raises in regards to levels in the tourney and maximum stack size to play all in or fold PF. I think it's in No Limit Texas Hold 'em by Daugherty/McEnvoy. I'll look for it and post it.

The phase of the tournament and the structure of the tournament is important and yes a book chapter would be necessary to explain this. Late in SnG's, the blinds are raising and orbiting the table fairly fast and you could not be the only one feeling a little short when you're down to 3 or 4 with 10BB's in the stack.

Different people have different arguments for this strategy adjustment. The main argument surrounds around the question, "Do I have the chips to protect my hand without going all in?" This includes asking, "Can I make a raise to protect my hand now AND on the flop?"