1) if you have problems with manually focusing, the AF confirm chip is OK for what it does
2) all the pin does is close the aperture in auto mode - auto mode won't help you and some adapters try to trap the pin
3) The old lenses were 42mm (hence the M42) in diameter, the new lenses are 55mm in diameter (Canon EOS, Nikon AX and DX, Pentax, Mijnolta maxxum / Sony; et. al - they all changed their lenses to the wider standard at the same time -- and they were all using 42mm before this but the M42 SCREW mount was a standard for Pentax, Practika, Mamiya, Yashica, Ricoh, Russian Zenit, Edixa, Zeiss Contax (the originator), Fujica, some Olympus, Exakta, chinon and cosina cameras (do NOT attempt to use without checking because while they screwed in, they had cam's to do Auto exposure and that may damage your camera) see wiki article here http://en.wikipedia.org/wiki/M42_lens_mount
NOTE: The pentax lenses (Takumar, Asahi) are overpriced, Mamiya is at least as good if not better and cheaper NOW (not then - new), The Yashica F 1.4 lenses were good (the F 1.9, etc weren't that good but as good as the Canon F 1.
The Zeiss lenses are fantastic and hard to find, the Practika lenses (pentacon, etc.) Meyer Optics are mechanically some of the best (22 aperture leaves !!!!!) but average quality glass; some were built by C Z Jena (Carl Zeiss East Germany factory in Jena) and are great; T mount lenses from Tamron, Vivitar, Soligor are medium to better glass, other brands quality falls down unless you know the manufacturer - despite the brand almost ALL 400mm f 6.3 preset and auto were one manufacturer; same for 500 F.8, almost all brands same manufacturer (even off brands like Spiratone, Cambron, etc.)
If you are not sure about a lens email me back the brand and F number; I have some of this already and know where to look generally7 for the off lenses
4) BEWARE the T and T2 mounts - the M42 has a 1mm pitch, the almost identical T and T2 have a .75mm pitch (the slant of the screw) so you could force the lens on and strip the lens or the adapter.(the T and T2 were lenses built to adapt to many cameras - they are short by a few mms so the adapters make them the right length AND change the 42mm x .75 to whatever is needed (Canon notoriously went with the same distance on the camera as M42 standard, just a different mount so the lenses focus to infinity as normal - Nikon, others have deeper bodies so they have issues and can NOT focus to infinity with M42. A T mount lens with a M42 adapter on it is the same as a M42 lens BUT --- Mant of the same chinese manufacturers make T mount to EOS adapters (also old Nikon to EOS, Olympus to EOS, and some more
NOTE: The T lenses had some good glass (soligor, Vivitar, Tamron, etc. put their better glass / mechanics on heir T lenses like Vivitar Series 1 (the premium quality and price series); etc.
5) In Manual (if the lens HAS a manual setting) you focus first, THEN move the aperture ring to the desired setting; On PRESET lenses (no auto at all) you must move the preset THEN move the aperture (or mo9ve them both at the same time - on some lenses you can move the aperture ring and it will move the preset ring at the same time) or simply leave the preset at the smallest aperture and ignore it; all it does is stop you moving the aperture beyond a point) On lenses that do not have a manual setting
6) he optix chip is interesting (here is one ad http://www.ebay.com/itm/100-M42-Eos-Adapter-Optix-V6-AF-Confirm-PCB-Chip-Canon-EOS-OP6002S-/380402645479
) but I have never seen one and yes the set up looks complicated - but the focus adjust feature does not appear to work as you might think (moving the lens) but rather telling the camera how far it is off focus of the same canon lens (which might work -- there have been problems with this chip in some users hands so might work like a microfocus adjustment) Do understand that users have reported this Optix chip is slow - slow to focus so still objects are better - sports, etc. is just plain useless
7) read Mt Spokane, A V mode is questionable - sometimes these adapters get it way off; use manual for best results
the 1100D does NOT have interchangeable focus screens, some of the higher end Canons do (dating back to the Canon F-1, A-1, AE-1; etc.) film cameras as well as the EOS5 / A2 / A2E FILM and subsequent - don't worry about this
9)No, don't ever focus using live view - live view is useful for framing, not focus. Use the Viewfinder, it is much more accurate (essentially live view gives you a very very low resolution image but the viewfinder gives you a far far higher resolution image, many times the resolution of live view