Hi Chris -
Welcome to Qatar ! Great to see one more RC flyer joining the RC community here.
Most of your questions are already answered in other threads on the forum, but I will try to summarize them here.
1) The procedure for import (that is, if you are getting stuff shipped instead of carrying it personally with you), is to get a letter from the Qatar Scientific Club (QSC) and present it to the customs authorities. If you are carrying things in person, then typically no questions are asked. Worst case, you can always claim that you will collect it after getting registered as a member of the aviation division of the QSC.
2) Any frequencies are allowed AFAIK. The crystal is also fine, just need to check for conflicts with fellow flyers when you are out flying, just like you do anywhere else.
3) You can expect everything to be about 25% (or more) higher in price compared to US online sellers. So bring as much as you can, but too much may cause you some hassle in customs.
4) Many people fly electric (airplanes and helis).
5) Where to fly and license requirements are answered here:
http://rcqatar.com/rc-in-qatar/rc-flying-beginner-in-qatar/6) Yes, every weekend, and sometimes during the week
