Couple of points: Yes I find WW2 weapons interesting and No I don't expect everyone to like them. This is why I suggested an SRC or JG G36 or a cyma AK before the sten.
A burst wizard Mosfet is a plug and play mosfet. It has 2 small Tamiya connectors and you plug it into the gun where the battery goes and you plug the battery into the mosfet. I would not consider that to be taxing for a beginner, although you can wire it into the gun as you would any other mosfet for additional functionality.
Yes a G&G combat machine is a good starter gun but so is a JG G36, a cyma AK, most MP5's... And yes the Sten is a suitable beginner gun if that person has stated that they play woodland (as opposed to CQB) and has said they would rather not have the same gun as everyone else. No-one is going to actually listen to that however, unless they see a Sten and think 'wow I want one', so I am safe in using it as a way to illustrate the range of guns available that are high quality, low budget weapons suitable for beginners. I just think we are too quick to think beginners gun=Combat machine without even reading the posts from the new players and asking questions. This is why I suggest that a new player gets a pic of their ideal gun, as I am sure we can between us match a gun pic to a suitable starter weapon and contribute to a bit more diversity at skirmish sites
From the original list that the OP made, I would suggest that the ICS L85 might be more of a 2nd gun rather than a beginners weapon. A TM G36 might be more money than you need to spend for a G36. TM guns are very high quality but there are some very decent G36's about for a lot less. CM16, yes a good choice for a beginner, all the previous answers about them cover it, I just think its the boring option.