A Few Breeding Questions

I have 4 RBP's that are approaching the 6" range ..noticed a couple of them getting really dark at times and a little bit of chasing around going on ..this may or may not mean anything but got me thinking I should have a plan in place if/when it goes down

not sure if I'm going to make the full throttle commitment to raising a batch yet, from what I'm reading it looks like it will take a lot of time and I have to make sure my schedule will allow for it ..but def would like to ..I have a 40B and a 20L not being used, sponge filters etc..

now what if I can't, what's the move here? do I just treat the tank business as usual and let nature take it's course? maybe toss some brine shrimp in there to give them a chance? or clean the tank out of all eggs and separate the breeding pair?