I think I can respond adequately to all four. If not, feel free to post a reply requesting further clarification!
A) If you show up without a character you'll have to take a pre-made character. If you submit your character ahead of time, you can design it any way that you want. The templates are from a previous Alt event. You can certainly use them as a blueprint if you like, but they aren't required if you submit in advance.

This post has the submission information. It may have gone up after you posted this thread, so my apologies if this is redundant.
www.knightrealms.com/forums/index.php?topic=7629.msg0#new
C) My advice is to take a character profession that utilizes points (e.g., priest, smith, or as you said, healer) and buy a few spells or abilities and many points. That way you won't have too many rules to learn and will be able to do your few things many times in a game period. If you're looking for a role-play challenge, definitely try a priest.
D) Do as you said!