I'd like to look at the aggregated usage information at a user level.
Basically hoping for a tool similar to
htop but with the option to sum up all the processes for a user, for every user.
I think you want psacct (or acct on some systems). It will provide:
yum install psacct
sudo apt-get install acct
you then have to start the service
chkconfig psacct on /etc/init.d/psacct start
Then you can use commands...
display total login time of each user
display total of a user user
sa will give ps like usage stats... like
for processes and cpu minutes (this is the one you may be interested in).
I am not 100% sure if you want 100% htop compatible output, which is not what those will give you, but if you want stats like previous processes, percentages and usage, those two (out of all of those commands) will get you very close.
Most of that info was pulled from this article.