when you go to messages, then there is usually two menus to choose from on the bottom of your screen. on my phone it says "add" and "options" somewhere in those two menus should be a "entry mode" option or something similar.. after you click that just simply change entry mode from numbers to ABC, t9word or ITAP. whichever you have. hope this helps man.
hmm it sounds like something you need to talk with your provider about.. do you have text messaging enabled on your phone?
thats pretty weird.. when entering your email do it exactly like you would on a computer. Ex. Bill_420@squid.com... so do not leave any underscores, capitals, or spaces you normally have in there.