Hello! i work with VBA for last 5 years, and a lot of my scripts work with forms, databases and so on.
About Your Project:
1) Totally not a problem
2)Classic way of working with Database, so also no problems
3)I think there are wrong clearcontents script, so i am sure it is possible to do
4)Looks like, previous add function, that send you to sheet with data, i will turn it off
5)It possible to turn off autoupdate when user form open, So u will be able to input as many entry You need at once, and will have only one delay, when You close Userform
6) This is posible, but Google has much powerfull computers :) , if You have a lot of entries it will work quite slowly.
Hope for Your respond,
Regards,
Vlad