I'm not the best in the world at chess (rating on here is usually about 1750) but from my experiences in other endeavors and a little from chess I'll give your questions a shot.
a. Do what your comfy with, just because its a big tournament for you doesn't mean that you need to all of a sudden change what you do best, I would however recommend learning those openings at some point, in case you want to use them or just to improve your knowledge of the game
b. tactical puzzles are great, I think anyone would tell you that. Prepare by doing some tactical puzzles, practice some endgame play and brush up on the openings you plan on playing.
c. Typically 1.d4 d5 openings are more positional and 1.d4 Nf6 openings tend to be more hyper-modern and slightly more tactical however this is a really broad question and one that I'm probably not the best to answer (long live 1.e4! 1-0)
d. I have never heard in my life before that it is illegal to write a move first and unless this is a rule that was passed very recently I am 100% sure that you are permitted to do so. Many coaches actually encourage it for the same reason that you listed.
e. ( i know there was no question "e" but..) have a blast it should be fun and a great learning experience. Meet some new friends and just have an all out good time, if it isn't fun why play.
Good luck to you, I hope this helped. feel free to message me with other questions...
Okay, I'm the high school chess champ in my state. In a little less than two months, I'm going to be at the Denker Nationals tournament. I usually play the French as black against e4, and slav/semi-slav against d4, and 1. d4 as white. I own MCO-14, which is more than good enough for my theory, but it's a lot of info to digest all at once. I want opinions, especially those of higher rated players, on:
A) whether I should spend time learning something more "mainline" against e4, like the Ruy Lopez or the Sicilian?
B) Are there any specific tips you can give me about preparing for the tournament? I understand positioning fairly well, and I score in the 1800s-1900s on tactical puzzles. Should I do more puzzles? Any recommended books?
C) Assuming I keep playing 1. d4 as white, what openings in the queen's pawn's openings are the most aggressive for white? Which are the most theoretical and positional?
D) Is it, currently, legal to write your move before you play it? The only teacher I ever had said yes, but since then I've heard lots of different opinions, even from TDs. I like to do it, because sometimes the act of writing it makes me notice that it's actually a blunder, but I was accused (and acquitted) of note-taking. Anyone who is more "in touch" have an opinion?
Any answers to the above, as well as any other general tips, are very much appreciated.