I'm not familiar with this particular system. The following apply to pretty much any canister stove.

(1) I don't cook in my Ti pot, just boil water to rehydrate dried food (which I do in a freezer bag). I also brew tea in my pot. A quick rinse is sufficient. Do note that if you're doing real cooking, titanium has very poor conductivity--there will be hot spots that burn your food and cold spots. You can overcome this to some extent by constant stirring and moving the pan around on the burner. However, if you want to do real cooking, you're far better off with aluminum pans.

(2) As long as stove and canister both work with a Lindahl valve, it makes no difference what brand you use.

(3) You need a special setup to use a canister upside down. For safety, there needs to be a shutoff valve at both the canister end and the stove end of the tube. In your case you evidently already have the remote canister setup but you need to find out if you can use it with the canister inverted. I definitely would contact Primus about this before trying it. Some say it's OK without the extra valve if the canister is kept lower than the burner. Yes, the inverted canister is much better in below-freezing weather because the propane in the mix doesn't evaporate off. If you don't use the upside down canister, you need to warm up the canister before use. I put mine under my jacket in my armpit for about 20 minutes (a really good waker-upper). You have to keep the canister warm during use, too. There are some BackpackingLight articles about this, but you have to pay for membership to read them.

(4) Per the Primus website, the liner is polypropylene, a form of plastic. You definitely don't want to cook in it--you'll melt it! If you're going to eat out of your pot or out of a freezer bag (what I do), leave the liner at home. Just pad whatever you pack in the pot.