Not a "contract guy" but I'll take a crack at this one.
Just to get your terminology correct so Scheduling will understand you better...There is no such thing as a "comp day." They are called payback (PB) days. Also, days off are called X days.
I think I understand your ? correctly, but to clarify, this answer is based on the following: Your schedule is 1 X day, 2 RSV days, followed by another X day. Hopefully I got that right...
You will get one Payback (shows up as PB and/or PR on your line) for each X day the trip covers. If you have RSV days remaining in the current calendar month, scheduling automatically places these PB/PR days on your subsequent RSV days. You don't get to choose where they are placed. This is also where the term "rolling thunder" comes from, as your X days become PB days and are "rolled" forward to cover up your next RSV days <----still with me?
If you DON'T have any remaining RSV days for the month, the PB/PR days will go into your Payback Bank which is viewable on your Time Card in iCrew. You should keep an eye on this, as this process is manually accomplished and sometimes things fall through the cracks.
To get back to your questions...You will be paid Single Pay/No Credit (No Credit means the GS will not offset your RSV guarantee) above your RSV Guarantee. A plain English example:
RSV Guarantee: 80 hours
Your Credit for the month to date: 60 hours
You fly a GS worth 12 hours
You receive pay of 92 hours
Your Credit for the month remains at 60 hours with a RSV Guarantee of 20 hours
Your situation is a little more involved as 2 of the days operate on RSV days. In this case you will receive Single Pay above Guarantee for the value of Day 1. Days 2 and 3 will count as Credit, offsetting your RSV Guarantee. Day 4 will then again be Single Pay above Guarantee, but no credit.
Additionally, all soft-time (also known as credit, confusing huh?
) is allocated to the last day of a rotation. This means that if you fly a 4 day as a RSV that is worth 18 hours, but you only blocked 10 hours hard-time, then the 8 hours of soft-time (credit) will be allocated on day 4. In your case this is a good thing, but it could just as easily screw you if day 4 happens to be a RSV day <---This is Honors Level GS sharpshooting, but something you will want to keep an eye on.
To answer your 2nd question: Yes, RSV guarantee is ALV-2 BUT never less than 72 or more than 80.