sorry for the late reply. Since the steem that is send is not lost the main question is which is more profitable. Having it in a group account which grows much faster since extra is put on top with a lot of mechanics in place to increase the value for the shareholders or have the steem in your own account. All the celculations can be done and the main question is how fast the account wil grow.

1. There is indeed no things as free money and it has to come from somewhere. This is where my personal investment comes in (the program should give me slight higher curation rewards but still far less compared to doing 10x self upvotes with the SP I invest). Everyone who gives up on steemit will also add value to the entire group since shares get destroyed and there is a small exit fee. (unless the programm stops after which the steem is paid back in full)
2. I did the calculations and it's quite close. This leasing is very limited just to give upvotes a bit of extra worth. All the numbers above are bare minimum promised numbers and don't include any delegation.

I hope these answers makes it all more clear, thanks for the feedback