As you know, the game penalizes you for actually killing enemy soldiers.

I happen to have a small problem with 'Target Burma' - seems I will have to replay it - and I want to ask - Is it possible to complete the mission with just killing silently and no tie-in up? Will the statistic 'Enemies eliminated without killing' not count into the general statistics, then?

I wasn't aware you were penalized for killing. Good thing I don't play for score because a) half of the time you tie someone up they escape and b) you can't beat some of those missions (Saving Private Smith) WITHOUT killing everyone. The biggest difference in finishing stars I've found is by completing EVERY mission objective, even the silly ones like using the elephant, and of course avoiding alarms which if you are careful enough really isn't that hard, minus the missions that end in pyro of course.

I've never played for score in Commandos 2. Being penalized for killing just seems counter intuitive to the gameplay. Pyro went out of their ways to give every commandos new ways to kill, loudly or silently, individual guards or whole squads: knives, tripwires, grenades, traps, mines, rocket launchers... It just feels weird to give all this stuff to the player but then says "But don't kill anyone with these."

I actually played the Burma mission by tying most of the enemy soldiers. But when the tyrant came to visit these were all freed by the new soldiers and killed afterwards by my Burma soldiers that I had put in an ambush.

All that work for nothing.

You can throw them down into the well/sewer but that might actually kill them I'm not sure, also you can't do that to the guys on the ground level. Man I love this game, so glad I decided to grab it on here so I can stop worrying about losing my discs.

The easiest way to avoid this is just storing them in buildings. You don't need to do this for all tied enemies,but just for the ones that are visivble to the tyrant's group crossing the bridge.

Depends on the building. In Night of the Wolves I jammed them all into one of the side rooms of the hangar and just as I was getting ready to make my escape they all came running out of there. Put a real hitch in my plan. :D