Scheduled Script Best (and fair) Practice

Hello All,

I'm currently in the middle of designing a workflow for a monthly billing system. A basic run-through of what I'm trying to accomplish:
1. Customers use my service, each time represented as an item on Sales Order
2. Sales Orders are completed and transformed into Cash Sales, using Customer CC details to complete payment process.

I intend to perform this process using 3 scripts, these are:
1. Build Customer List, use nlapiScheduleScript to generate a job for each customer.
2. For Each customer build the sales order
3. Collate ALL Sales Orders and complete transactions.

My question is, the potential is there for the first script (build customer list) to generate a large number of scheduled script (over 100 easy). Now I realize that they are all run consecutively but still, there has to be a limit.