1. Red locomotives appear
2. Ae 4/7's begin to fade away
3. Re 460's appear
4. Rect. headlamps and angled front handrails appear
AFAIR the first locomotives with the rectangular headlights were the prototype Re 4/4IV 10101-10104 (1982).
That type of headlights were then installed on Re 4/4II 11178 and then on the final production run (11371-11397). In the 1990s with the addition of new UIC connectors, it was decided to add steps and railing to facilitate crew access to the socket.
5. Air conditioning on Re 4/4 II and Re6/6's appear
6. Re 4/4 I's begin to fade away.
7. Steuerwagens and push-pull trains appear
At some point in the 1980s, the Re 4/4II were authorized for operation with EWII BDt and EWI BDt
I don't know exactly when the first Re 4/4II push-pull consists went into regular operation. The EWIV fleet was complemented with Bt Steuerwagen made from converted Bpm EC coaches in the mid 1990s. At around the same time, coaches of the EWIII series were also converted into pilot coaches to make those trains push-pull consists as well.
8. Red and blue CARGO locomotives appear
Markus linked this turning point to #13. I would think that the larger turning point would be the split of the SBB and it's locomotive roster into Passenger and Cargo divisions (1999-2000). There were several prototype cargo liveries before the Red/Blue livery was chosen. The first locomotives to receive this livery were the modified Re 4/4II of the final production series (11371-11397), which were adapted for use in Germany and renumbered as Re 421 371-397.
I am sure that Markus can provide you with the dates that the fleet was divided, which units were assigned to which division and what changes followed, leading to today where all Re 460 are assigned for passenger use and all Re 6/6 (620) are assigned to cargo operations.
9. IC-2000 coaches appear
In addition to the introduction of the IC 2000, there was also the introduction of the new EC coaches starting in 1993. This meant the classic RIC coaches started to fade away and the remaining ones would be repainted in Intercity colours as inland coaches.
10: Wappen on Ae 6/6's disappear updated to include "and the Ae 6/6 begin to fade away"
It wasn't just the Crests that disappeared. People were taking the Swiss crest from the locomotive faces as well as pieces of the chrome striping on the so-called Canton-loks
11. ICN trains appear
12. Thurbo type passenger trains appear
I am presuming that by Thurbo, you actually mean the introduction of the Stadler Flirt and Kiss type trainsets, the first of which was the new trainsets for the Seetal line and was followed by the Flirts for local traffic and then the KISS for regional traffic.
13. The first "German made" (i.e. Re 482, etc.) CARGO locomotives appear
I would also recommend to add one further turning point (14), the appearance of other foreign and domestic operators on Swiss rails, including BLS Cargo, Crossrail, TXL, Rail4Chem, DB Schenker (DB Cargo/Railion/etc), NordCargo, Veolia/Captrain/etc.
You should also probably include the introduction of the EWIV Intercity coaches in 1982-1984, as the introduction of these coaches allowed for the EWI and EWII coaches to replace older coach types in local trains and the introduction of coloured coaches rather than uniform green also marked a major change for the SBB.
The next significant change is coming very soon, as the new double deck (Twindexx) trains are coming into service and the new Stadler trains for the Gotthard are still a few years away. As each new trainset comes into operation, we will likely see more traditional locomotives transferred to Cargo operations and the oldest Re 4/4II/IIIs and Re 6/6 will gradually be taken out of service.
Other milestones would include the sale of the EWIII to BLS, the BLS/BT and SOB EWIV going to SBB and the swap of the Re 4/4IV to SOB in return for four Re 4/4IIIs.