Ok, so I bought The Witcher Enhanced Edition Director's Cut and The Witcher 2 Enhanced Edition and I'm wondering are my games up to date?

1) My Witcher 1 EE DC Win game installer on GOG is ver. 2.00 so I guess I have the latest and most complete version of the game and don't need to patch anything, right?

2) My Witcher 2 EE Win game installer is ver. 3.0.1 but I noticed patch 3.2 and some hotfixes on official Witcher website. Do I need to patch my game to 3.2? What about hotfixes?

Lastly, as I understood, GOG games come without cd keys (drm free) and cannot be registered so in this case I cannot register Witcher because I did not receive cd keys, true? Thanks.

Yep. The GOG version of Witcher 1 is the latest one. None of that is necessary. 3.1 fixed some problems with saves made before the Enhanced Edition, 3.2 includes the popular "panel tweaks" mod, and 3.2.1 made some improvements to the Chinese language in the game. None of it is essential. You should receive a CD-key in an email anyway, unless that changed since the game's initial launch (which is possible). At launch, the game was DRM-free but there was some DLC that you needed a key to download. All DLC has since been included in the patches, so it's possible that they did away with keys altogether. You might check your email to see if you got one, just in case, but I wouldn't worry about it if you didn't.