I understand your frustration...but all those problems can be fixed!..though I'm not entirely understanding your first problem.
2-Go to this link (
http://forum.xda-developers.com/showpost.php?p=3296423&postcount=382) and download the .cab attached in the first post. If your on you PC, you will need to transfer it to your TP, then use file explorer to open it. It will self install and eliminate your screen from going black. However, this will wear down you battery significantly (the reason it shuts off in the first place) so keep that in mind if you talk a lot.
3-There are A LOT of mods that can be done to spare battery life. The most important, however, is making sure you keep programs closed. Factory settings allow for "minimizing" programs when you hit the "X". This should be changed so that when you hit "X" the program is closed. To do this, from the today screen, hit the three bar button int he top right corner. Then click the wrench and specify this option.
Also, using "close all" (stacked "x"'s in that same menu) will close Active Sync for an extended period of time (which also wears down battery life).
Aside from that, try "Advanced Configuration" to set things to your liking. It has some power management features to it.
Hang in there! Your not the only one with complaints...you just have to do some digging to find the .cabs to fix all the annoying little things.