You gotta be kidding me. What on earth did you trade to get this tub with that many jets? Awesome man.
We prefer to belive that most of the hardened equipment is probably GOOD and not yet dead when it comes to replacing a system in order to save money. I'll bet that they're probably still ok.. the pump and blower that is.
If you're wondering what to set that thing on... I've seen them all, and I'll tell you, it all depends on the capacity of the earth to support it evenly over the space it occupies. (Duh?!

From very recent experience, (in the last couple of weeks), I've seen one spa installation that was done on a full concrete pad (with rebar reinforcement) that tilted about 8 degrees aafter a year which ended up with the water almost overflowing the side on one end, and yet even with the skimmer middle level on the other.
The second was a spa shell built into the deck that had a gas heater that I converted to a STD1000 electric heater/controller install - and at 15 years old, it only had a tilt of about a couple of degrees, and it was supported by about 8 different points, with the base and seat supports end up sitting in the dirt/clay - just those concrete brick things you can buy at Home Depot for about a buck a piece.
You can never tell about the earth a hot tub sitting until you put 3000 pounds of weight on it. Pavers, rocks, bricks, right on the backyard bermuda grass - hey, they all work but be prepared to move it or do some adjustments later on if it starts to move or tilt. There are no guarantees.
For your particular self contained hot tub, be sure that the base of the spa, (the center), is supported well. That's the most important thing. You never want to hang a spa shell from the edges like in a deck installation. The best way to treat a tub shell is to be certain that all of it is supported equally. Most self-contained tubs like yours will never have a problem with this.
You asked about ants. Ants love spas. They eat the insulation right out of them and camp out.... A hot tub is like a summer home for ants (as well as squirrels and mice). Use appropriate measures (bug bomb) to get rid of them).
As for flushing the lines out... heh... get the thing up and running again, shock the heck out of the water (a couple of cups of clorox will do the trick) and you should be fine with whatever's invaded your tub territory.
Ummm... back to saving you money again (nobody likes a spa that's a money pit) -
Now on to cleaning the tub itself........ (chemicals and such)
Drain the thing and wipe it down with kitchen towel if you like. That's about as good as it gets. If you wanna get into the science of polishing perfectly good acrylic with turtle wax then fine, but don't waste your time, in my opinion.
Let it go. This is not rocket science as some make it out to be.
Oh yeah, last thingy, remember that the less stuff that you put into your water, the better you and your equipment will be. Just keep the ph straight and you'll be good. Check it once a week or so (minimum every 2 weeks), and you should be ok.
For a control system to replace what you've got, with minimum alterations/modifications, check out this one:
STD-1000
Be sure to look at the photos associated with it.
Any other questions, I'm at extension 105 - otherwise just ask for Terry, Jeff or Barb and they'll help you just fine.
Best of luck.