Make the side bar max height for that of the viewport height. Make the Groups and Friends sections toggleable close / open and scroll bars within.

Prioritize payments and do calculations based on them. Say an old payment exists in my dashboard and i don't wanna delete or settle it but just ignore about it when seeing my total.

Make dashboard items selectable so that i can calculate or get a total based on the selection items from my dashboard.

Same scenario mentioned above with selection of friends and groups from side bar or on a new page would be great.