Adding Charge to Reoccur in Subscription Plan

Adding Charge to Reoccur in Subscription Plan

We have set subscription plans for our product, however, we can adds on more ingredients to the product (is a vitamin) and this would add on a fixed price regularly. Can my developer put in the charge onto the subscription plan and make this charge stick regularly? There maybe upto 5-10 charges, and the combinations can differ.

3 other Questions:
1. Can we assign more than 1 plan per person?
2. Can we make a custom price based on the ingredients or products purchased together?
3. Can we charge add-on's every 3 months like the plan? I only see add-on's at weekly, monthly and yearly

If you have any idea on how to implement something like this, it would be great.

Lastly, do you have any developers you recommend for implementation + using Stripe,