1. I have no idea about the pictures.
2.
CDMA- This is the type of cell tech that Verizon and Sprint use. It's simless, so you can't swap sim cards in and out. P.s. SIM cards are very different than MicroSD cards.CDMA is also pretty much only used in the USA and Japan.
GSM- GSM is what ATT, Tmobile, and every European Carrier uses. They require SIM cards, which can be switched in and out at will.
UMTS- UMTS is 3g on a GSM device
LTE- LTE is 4g on GSM, however, all CDMA carriers have decided that they will use LTE on their phones. This is the first universal cellphone standard ever. However, only global phones can use the services world-wide becuase the different radiowaves that each country runs the LTE on.
Global mode - I think you mean Global Phones, these phones are GSM Phones that can operate on 4 or 5 different frequencies, so no matter what country you're in you should get service. In the case of CDMA global mode is when the newer CDMA phones use their built in SIM card for use in other countries. You typically have to call your service provider to get this activated.
If you have any more questions use a quick google search and check out the wikipedia pages for these topics. They go more in-depth than I do.
3. I don't know if high-contrast mode consumes more battery, but 3g, 4g, and bluetooth do consume more power, also wifi consumes power, and if you aren't using it, it is recommended that you turn it off to preserve battery life, but WP8 and WP7 currently automatically disconnect you from wifi when you lock the phone, so it isn't really that power savvy to turn it off in my opinion.
wifi consumes the least power, to my knowledge, then 3g, then 4g. The more data you are sucking in through your phone the more power you're eating up. Also, 3g and 4g access points are much farther from your phone than your router would be so sending and receiving data takes more power because of that. So use wifi when you can, and only use 4g over 3g if you are streaming videos or downloading stuff. Wifi is typically faster, but apparently you can get faster speeds on 4g than you can with wifi, but I, personally, question the validity of that.