Mods, mods, mods the sky is the limit

[joho]

Been reading a lot about mods in this forum.

I am running GWX2.0 and Commander and it works fine.

Now is there any known problems with other mods. The cumulus clouds in the sky, survivors in rafts and life boats, torpedo damage, sea battered sub skins etc. etc.
Or can I just rush ahead and download anything I can get my hands on.
And can I upgrade to GWX 2.1 without loosing game progress?

I am a bit worried that my game may break and / or horrific loading times.

Most gratefull for an answer.

This forum rules as do SHIII.