I'm sure Able did the best job they could given the specifications you gave them ("...best possible antenna setup without resorting to a rotator?").
The efforts people go to to avoid a rotator...
Seriously, if you put a rotator up there you could have perfect aim whenever you want it. For the majority of your channels it doesn't matter where your antennas are aimed. So you could be pointed right at ION, or right at CHCH and it wouldn't matter to any of the other channels except WBBZ.
At my house we have five TVs and an HDHomeRun with the dual tuners. Only one TV has the rotator beside it, but you would never know. Only CHCH and WBBZ are affected by aim at my place. So no matter where the antenna is TV viewers in the other room have no idea where the antenna is pointing unless they happen to be watching CHCH or MeTV. There has never been a conflict.
Consider it...especially since you have to go up there yourself again or pay someone else to go up.
With a rotator, you would have a YA-1713 fixed on WBBZ below the rotator and maybe an Antennas Direct DB4e with its strength and wide beam width for the rest. After CHCH and CTV2 go to UHF, your VHF antenna will only be needed for WBBZ.
If you want to be able to dx with your VHF antenna put it above the rotator.
Keep your pre-amp.
WBBZ might get stronger with a better antenna. My experience with WBBZ says you need perfect aim to get a steady signal except for during the hot summer season. If you have a roof tripod consider a YA-1713. Make sure you have a good mount.
You could sell your C5 for almost full price in the Items for Sale thread on this site.
Best of luck. Post back what you end up doing.
If you're going to consider a rotator but you're afraid about the quality of newer rotators, there is a Digital Home member called Southgate and he is an OTA hobbyist near you. He has several vintage rotators from the 1970s and 80s. He cleans them up and gets the ready for another thirty years in the sky. Mine is from him.