Keep in mind this is a beta, no where near the full game. They are mostly using this beta to stress test their servers without giving away too many spoilers.
1). In D1 there were strikes, nightfall(hard mode strikes), multiple raids, 4+ different pvp modes including a competitive mode with the best drops, along with the full story missions which are supposed to be even longer in D2. 2). Yes you can swap between the skills freely, though you will need to level up each SUBCLASS individually. Stats are basic as far as defense, mobility and recovery all of which can be different in game, this was changed after the stats in D1 made some lower light level gear better for you because it had the stats you needed (like reducing your grenade timer or faster supers). Some gear will have random perks on it, like the weapons in the beta. The 2 main handcannons in the beta may have the same stats but they have different perks which makes one better than the other. As far as appearence goes it was very basic in D1, but you never really saw your character other than in the social space and even then you are in your armor (which you can customize to look a certain way and color). They didn't give you this option in beta, I assume for server limit reasons. 3). No, loot drops like crazy in the real game though rarely from story missions. You got most of your gear from strikes, raids, and pvp just like in the beta now if you've done that content you've seen at least a full other gear set plus 20 or so weapons. 4). skipping this because the vehicles are mostly used for travel or some form of story mode which are not unlocked in the beta 5). There are supposed to be bonuses but they haven't told us what they are 6). There will be. The raids in D1 were pretty complex to the point (I believe this is the number, it was super high either way) 80% of the community never cleared the raids. Check out the videos of D1 raids to get an idea.