Lean how to file properly, including the rakers. A sharp chain is very important to your saw,it should pull itself through the wood with out having to push at all. If filed properly! oregon makes a little filing guide book that has some good pointers. Good Luck fighting C.A.D
That's not a good idea. No, it's mandatory, if any saw is to get work done. It's the key.
Granberg and Oregon clamp-on-bar file guides are IMHO the only ones worth a spit for quickly, with minimum metal removal, getting cutters razor-sharp. And, I'm guessing about the Oregon.
When to sharpen: eventually, you'll know from look/touch. When output turns from chips to dust, when you hear anything "funny" near the chain or see sparks. Taking five to touch up the cutters is a useful break.
When pinching is possible, be ready in an instant to pull the saw straight back out of the cut. Don't bend it! Beforehand, make sure that nothing will be in the way. Note that this makes long bar sub-optimum.
Running a saw well and safely is like the joke about getting to Carnegie Hall: practice, practice, practice.