Are you adding any elevator to the plane when it is gliding? It just sounds like it is stalling. You can change the neutral position on the elevator to correct this, but I would not worry about it since I don't think that is a huge problem since the plane glides well up until that point. As for the plane crashing when you throw it, sorry to say that is most likely your little experience. With full throttle and a good toss, the plane should have no problem taking flight. But, I could not say for sure since I usually take off from the ground since I hate tossing. I find the ground a much safer place to start from.

And you made a good choice by getting flight sim software. It will help you a lot. You can keep crashing the plane (and not waste money) until you finally get the hang of it. Thats something that I should have invested in when I was learning how to fly (I taught myself). But, make sure you are very good on the sim before you start risking your plane again. You will be kicking yourself if you don't and then total your plane. Trust me. Good luck.