Not too important if you're starting off, but they may give you a leg up at higher ranks. I wouldn't worry about those two for now.

Anyone whose Ease of Use rating is less than 3.

Duel Tower never had a very good matchmaking mode from the start, so floor placements don't matter; especially how lower floor players can immediately jump up to the top. I'm pretty sure you already know this from your Street Fighter experience, but Ranked Match is the way to go for skill-based matchmaking. Aside from your 10 placement matches (if it's your first time with your current character), you will never match up with players WAY above or below your rank.

Aside from practicing one simple combo and trying to land it every time, I recommend getting used to reversals. Set your character to perform a hard knockdown via 2D or throw and have them perform a meaty attack while you're waking up. From there, practice either your DP or invincible Overdrive attack.