As said before, to fix the window view, hit views, the check full screen. To get out of full screen, hit ATL
and that will show the toolbar at the top.
Ahh, the neverending problem with framerates
As you increase your display and the quality of the world around you, you at the same time decrease your framerates. If you do not have a good graphics card and processor, I would recommend putting scenery on "Medium High", which gives enough scnery and enough realism to make it look ok. Also, on the top of the "Display" menu, go under weather and drop it down to "Medium High". Anything higher drastically reduces frame rates. Also, when you are in the air and looking down at the clouds, you will for some reason get much lower framerates than if you are looking up at them (dont ask, thats what i have noticed on my machine). The last thing, next to the weather tap is "Hardware". Put the resolution on 1064x800x32 (not exactly sure of the numver but its the last option). Also, turn "Anti-aligning" off, and put it on bilinear. This should make framerates jump a bit.
Hope it helped
Hold it . . . Hold it . . . HOLD THE FREAKIN NOSE UP!!