Bruno MarcMen's Chukka Suede Leather Chukka Desert Oxford Ankle Boots

Can you wear these in the rain. Are they likely to get ruined

Does the sizing go by the us or uk system? I take a uk 11 but the description seems to say otherwise & I just want clarify if I should get a 11 or 12.

Would these fit a 12 wide foot - the size chart has no measurements

Can I remove and replace the insoles