Try hooking Stripe up to any third party analytics dashboard. You won't get an accurate MRR.
It really sucks if you want to have Stripe metrics in front of your team.
That’s one of the options, yes. Chartmogul does an amazing job at ingesting and retrieving revenue data from stripe
If you have a single type of pricing(eg, variable, or tiered) its very easy rolling your own.
The issues happen when you change from variable to tiered(or vice versa), change from anniversary to calendary dates, add coupons, per user custom pricing, credits, etc etc.
I don't recommend building your own if you aren't familiar with Stripe or any other billing system. Once you understand how billing works, feel free to make a custom billing solution.