I picked up a Lamy 2000 EF and the first problem is the cap is easily twisted when its on. Clicks on securely, but is this a problem? Second of all, is the nib arched THAT much, or is mine dropped. Writes perfectly. Also, how do early Lamy 2000s look?

I have the same pen. Yes, the cap rotates when the pen is capped. No problem.

Yes, the nib has an arch. 2000's do not have a flat nib surface on the top. A picture might help determine whether yours is more arched than it should be.

Will post pic later. My other 2000 doesn't rotate at all and the cap bites hard

I have a couple 2000s and one has a firmer "bite" than the other when capped. Likely to do with the little metal ears on the body. I'm sure if you took the cap retaining ring out and expanded it a little, it would give more grab on the cap. I prefer a softer click upon capping. Never had a problem with the pen uncapping itself or the nib drying out. So long as the cap remains secure, I think it wouldn't be a problem.

Any pics of the vintage ones?