It's an issue of tuning. Sure you can let them do that if you like, then be aware that your PCs will be somewhat more powerful than their standard counterparts, so you'll possibly need to adjust their challenges accordingly. It's okay IMHO if you want a more 'heroic' campaign, so to speak.
It's more like the DM can tell you to roll a d20, and if you roll a 1 you roll on the Wild Magic Surge table. If you've already used your Tides of Chaos feature that day, the DM can tell you to directly roll on the Wild Magic Surge table instead, and you regain the use of Tides of Chaos.
I completely agree. But isn't the bows being clearly superior thing fixed with the damage changes I proposed? I think it's better that way than 3e for the same reason you've explained in your post, because it makes all of them mechanically relevant at least for some characters.
I personally prefer the system we currently have in the playtest. Have you read the equipment document in the playtest packet? The loading property doesn't mean that you spend an action to reload it, it means that you can't attack with the weapon more once in a turn. In the 3e system, I don't...
Looks like they've seriously messed up ranged weapon balance. There is no reason to use the crossbows over instead of their normal bow counterparts. They do the same damage, but have the loading property, which is a disadvantage. It should be like this: (which it was in the last packet)
Light...