I guess the first question is: what is the best way of using your SP to achieve your aims, which at the moment, seems to be to grow your SP? Would you earn more by keeping your voting power as it is, or delegating some of your SP for other returns and reducing your voting power and curation rewards?
You have to have some shares with sbi in order to delegate, and I believe each share or bonus share has a vote value of 0.0024 (this does change so may not be the latest figure) each week. So you could work it out :)
Eg 5 shares plus 190SP delegation = 100 shares x 0.0024 = 0.24c a week or 0.034 each post (I think). The great thing about delegation is you can stop doing it when you want to :)