I've also encountered multiple radar bugs with the F18 Hornet while in TWS mode. While testing certain missions I use as a baseline for air-to-air engagements (local missions, not multiplayer), several things are making it extremely difficult to engage multiple targets while in TWS mode since the 2.7 update.
Several other things I've noticed besides the ones mentioned by the OP:
BIAS mode seems broken, or at least extremely sporadic while trying to select from AUTO mode. This used to work well before 2.7. It seems to work without any target in range / scope but I cannot get it to work while engaged. Maybe I missed a changelist bullet...
AI targets seem to react immediately when firing AIM-120Cs in TWS before the missile goes pitbull. Confirmed both visually and in TacView. The cool thing is that it appeared as though I could see the enemy chaff on my radar; is this a new feature?
When firing 120Cs in TWS mode and slowly moving to offset right or left, or cranking to radar gimbal limits, the missiles will show LOST for a brief period and then finally re-acquire. Doesn't seem to make a difference whether you crank hard or gradually.
Similar to the 3rd bug mentioned by the OP, consistently losing a lock while cranking right or left (4-bar vertical scan, 40 degree sweep) results in 120Cs flying stupid. Usually the 120Cs end up heading towards outer space or attempt to acquire at a very late stage.
I believe one of the changelist items mentioned that the radar range on the Hornet was nerfed. This is evident in that you typically cannot get a lock past the maximum range of a 120C. Usually the first lock occurs when the target is in range to fire, again making it difficult to bug multiple targets before they enter max range. Why??
Overall I was happy with the previous TWS behaviour, it seemed to work OK except for the occasional issue where the scan would pause or lock up when cranking right or left. If some of the changes to the radar (such as MAN mode) fix behaviour to make it proper, then I'm OK with that.
IMHO, I would say the most annoying issues would be consistently losing the TWS tracks and the AI receiving a launch warning before 120s go pitbull.
Otherwise the new clouds, explosions, visuals, etc are stunning. Great work there!
I almost wish I could test alpha builds before they land in Open Beta.