Your interpretation of Coupe Sport Injected sounds about right. I believe the only cars since the early '70s badged "CSi" were a) all the 6 series cars except the M6 and L6, and b) the 850CSi's, the sports version of that car (it was telling, I think, that the standard 840 and 850 coupes were badged "Ci", i.e. they left the sport out. The original (pre-6 series) BMW coupes, the beautiful 2800 and 3.0 coupes of the very early '70's, were badged with the "CS" suffix, for coupe sport, and injected 3.0's were CSi's.

A couple of more wild cards: you probably realize that all "M" cars are specials from the M (motorsport) division of BMW, which originally really was the racing division before it went into the limited production car business, similar to AMG for MB. An internal BMW rule is that in an M car, a) the engine has to be something special, b) suspension must be upgraded, and c) it has to be a manual transmission. With that in mind, there have been a number of "semi-M" cars built over the years that had one or more of suspension, engine work, or manual but not all three, and hence no "M" designation (but still very desirable cars). Among these are the 540iM package in 1994-5, a 6-speed V8 with upgraded suspension whose owners think they're worth M5 money (wrong), the 740i Sport package from 1999-2001, which has a great suspension but the stock engine and an automatic, and the current X5 4.6is, which has the upgraded engine and suspension but no manual.

The L6 was a "luxury" edition of the 635CSi, sold for a couple of years in the late '80s and meant to stand in contrast to the M6 which was released during the same period. Kind of an odd duck. Also, there were "e" series cars in the '80's, the 528e and 325e; these were detuned cars built for, apparently, "economy". They were decent, very durable cars, but not especially exciting.

The 2002 tii was the fuel injected version of that car; the other versions were carbureted (remember, this was the early '70s when fuel injection was a big deal). The "ti" part of the 2002 designation had no relation to the later 3 series hatchback compact, despite the similarity.

The original BMW V-12, introduced in 1988, was 5.0 liters, and was badged 750il (BMW has never made a short wheelbase version of the 7 series sedan). In 1995, the engine was reworked and displacement bumped to 5.4 liters, but as with the V-8, the badging wasn't changed - it stayed 750il. A entirely new V12 was released this year for the E61 7 Series, it's a 6.0 liter engine and the car is badged 760il.

BTW, if you're ever shopping for a used Bimmer and you see an "a" at the end of the number in the ad, e.g. "530ia", it just means it's an automatic - again, that's an informal reference, you'll never see it on a decklid badge.