Q1. Does the fry pan serve as the pot lid on the kits? If so, is it hard to grip the pan with those pliars, and how firm does it fit the pot? Do most not use a lid?
A: Yes. It is not difficult to grip because the diameter is quite a bit wider than the top of the pot. Just turn the grippers upside down. It fits quite OK for simmering. If it was a tight fit, you may face an explosion! But, generally, everything works well. As to the frying pan side of things, the three little lugs that hold the pots turn upwards and hold the pan above the windscreen. The lugs are pretty nifty because they are shaped so the frying pan won't slip off the stove.
Q2. Could someone tell me the diameater of the round base that doesn't have the wind screans attached?
A:Sorry, but you will have to be more specific. Do you mean the base that sits on the ground and to which the upper windscreen/pot holder attaches?
Q3. Does the pan sit close to the mouth of the burner? On the can stoves I have made it seems to work better if the pan is 3 inches or so off the stove.
A: There is some clearance of an inch or more between the burner and bottom of the pot. The fact your can stove works better with a higher position probably relates to the draft created for the stove. Believe me, the Trangia is a hot little unit when on full bore.
Q4. Does the simmer ring work well?
A:Yes and no. The simmer ring basically takes the jets out of the picture, and you are left with the pool of alcohol burning. Functionally, there is absolutely nothing wrong with this; if you are anywhere near a decent cook, slow and steady is what you want, even in camp.
But the weakness (and probably the most significant of all for the Trangias) is getting the darned thing off if you want to go straight from simmer to boil (ie, when changing to another pot, say, to boil water). I use the grippers to grasp the lid if it is open.
Otherwise, if the simmer ring is almost closed I just use the lid to the burner and place it over the top (upside down to preserve the O-ring) to extinguish the flame. I do this also when extinguishing the flame when the simmer ring is on there. Otherwise, I use the simmer ring, with the flap closed, and toss it on to the burner. This can be a hit-and-miss affair. I don't know if anyone else has suggestions on how to extinguish Trangia burners.
But long answer short... yes the simmer ring works well in controlling heat.
Q5. Should I just keep using the can stove?
A: It's a free world
The thing about the Trangia is that everything fits together well as a package, and you don't have to muck around unrolling windscreens, making up stands and be extremely attentive that hot pots don't fall off the stands. I've often thought about making up a can stove, but then I think "why bother"....