It is a small world. I didn't know your email address, so I didn't know it was you. Your two questions are pretty common ones.
1) If you have left your 760 on a full 24 hours and it says it's fully charged, and then 24 hours later it says it's empty, you've got a bad rechargeable battery inside and it needs to be replaced.
2) I have had a couple of Keyboards with the same problem of not being able to push a button easily to get it to work. This has been a problem I send out to a repair shop to have fixed. I've been told it is simply an alignment problem of needing to adjust where the button touches the switch. Unfortunately this seems to be a fairly common problem lately. I didn't used to see this at all, but in the last 6 months it has happened on several keyboards.
Look for that big box with the Pro 2 and the smaller one with the midi pedals to arrive this week.
Kayes' Music Scene
Kaye's Music Scene (Closed after 51 years)
West Hills, California