> 1. Do you need to light the stove with the canister upright and then
> turn it upside down once it gets going?
You do not have to do it that way, but that method does avoid any chance of a small flare-up.
> 2. I read that you should invert the canister at a very low setting (low flame).
> I'm assuming this is very important?!
Well, what you are trying to do is to keep the pre-heat tube warm. A low flame means the liquid fuel hits the pre-heat tube slowly.
And yes, I do this (carefully) inside my tent, especially if there is a storm outside. I prefer to be warm and dry, thank you.
> 3. If you have the option to invert the canister would it be wise to always to
> invert it, no matter the season? That way you use all the fuel.
You don't have to if the ambient is above (say) 5 C. Below that it makes sense to invert the canister as doing so means the fuel composition stays approximately constant to the end. See our current Cold Canisters article for techie info.
> 4. I am leaning toward the Primus Express Spider. Would you consider this
> a all around quality stove?
Yep. Not the lightest, but reliable and well-made.
> 5. Does the connection to the canister on the Primus Express Spider rotate
> freely? As in, does it swivel when you invert the canister?
From memory, yes. I think all Primus hoses have this feature now.