Percentage table must total 100% and has a limit on how many options can be entered on

Hello!

This is a tricky one at least for me to explain so please be patient as I try to explain this. I need to create a percentage table with fields that:

Must equal 100% (not less than, not more than). This could mean only one option is entered that must be 100%, or multiples (up to 14) that combine to total 100%.

Of the total number of fields/choices, only 14 of the total number of fields can be entered on. So, if a user has entered 14 of the fields in the table, they cannot enter on any other fields. They would need to remove a field entry (or entries) to enter on others (but no more than 14).

I'm trying to figure out:

1.) Is it even possible to only have 14 fields max be entered on, and if so, what happens if someone tries to enter on more? Are they deactivated, do they throw an error and clear that value out? I'm struggling to figure out how to solve this request. 

2.) How can the Total at the bottom of the table calculate based on 14 fields when there are actually more than that? It currently calculates the total of all the fields.

3.) Is there a way to conveniently have the form throw some sort of message when they don't total to 100% exactly (I can't think of a way to do this).

I am also open to suggestions in the event there is a simpler way to achieve this. I just can't seem to sort out the best way to make this work and could really use some help.

Appreciate and am grateful for any help... and please note that I am far from an expert and am doing my best to figure things out as I explore.

Thanks

I cannot figure out how to achieve