The forum ate an hour and a half's worth of consideration and typing just now and I'm rather upset about this so these points will be rather brief.
Alhatra/Reverse is a solid track, giving some of the best races in the game (or used to *charged powerups are broken grumble grumble*). Enough technicality to be interesting to drive without being excessively punishing. Doesn't mean it's without nagging issues and areas to improve, which I'll address in this post.
Murderous signage - there are red barriers and orange ramps that don't really help much and instead make certain areas more dangerous than they need to be. See these images:
The tunnel on forwards is quite bad, the red barriers effectively give people less space to make adjustments while narrowing the entrance itself. Maybe try playing with their angling so they shepherd cars into the tunnel instead of launching them skywards. It's a bit better on reverse since they don't overlap the entrance itself, but the barriers still make the profile of the tunnel on the track a bit wider and just serve as a nuisance to be hit.
The red barriers on the bridge pillar thing only really end up widening the hazard a bit, and don't make crashes any less punishing. Would probably be best to put a single barrier flat against the pillar as a warning, making sure it didn't overhang the edges of the obstacles itself.
The circled orange ramp is a giant trap, which almost always causes bad landings if you take it where driving anywhere else would be workable. The track design more or less points out where you're supposed to go, so IMO the ramp can be removed entirely.
Weird terrain and odd elements that don't seem to work quite right:
This bump is hard to see and can often cause trouble if a player has to pass over it - problem here is that it looks like a piece of track that it's safe to traverse but in reality will cause crashes a lot of the time. More of an issue in reverse, where someone may want to swerve across the outside of this section to avoid fire.
There's an invisible barrier covering most of the right hand side of the exit to these pads, making them deceptively dangerous. They're awkwardly placed and seem to want you to take them such that you bounce off the barrier on the outside of the bridge, which IMO shouldn't really be encouraged. Probably best to remove them, or adjust them to somehow be in line with the road.
My main beef with this is that the red barrier on the entrance to the loop looks like an obvious patch job and very out of place. The loop itself is quite punishing if you get it wrong, although it's got a lot more forgiving with the physics update. Ideally a different loop layout would be used here, since this one can very much still buck you off into an invisible barrier or the scenery and a painful reset.
This is a pretty hairy corner to take at speed, and it's fairly common to end up scraping that left wall. If you do, there's a fair chance that the car will ride up the wall, leading you with almost no way to recover into a dead stop crash into the pillars at the end. Possible solutions would be to either make the wall lean inwards slightly so that the car can't climb it or remove those pillars.
It's fastest to wallbounce off the concrete barrier the car's pointed at in this image rather than taking the corner properly. Maybe try removing that concrete object and all the rocks/stuff around it, so that there's nothing to bounce off? Unfortunately this would probably result in the optimal strategy going back to being bouncing off the inside wall of the structure, but at least that's a bit less safe/a bit slower.
I think this concrete barrier was moved to discourage bouncing off the wall in that corner. Instead, it murders anyone who goes a bit wide trying to take the corner legitimately while generally not doing anything to people bouncing off the wall. Would rather not have this thing in the way at all, it's very frustrating to hit.
Wasted potential/underpowered routes:
Powerups were removed from this route, which has left the loop route as objectively the best one since neither one awards pickups. If the pictured route had a set of pickups, it'd regain some relevance - or at least make it less of a disadvantage to take. Currently there's no reason not to risk the loop since if you don't take it and someone else does you suffer for lap times with no compensation.
Right hand route here is very slow and pretty unrewarding. Could probably use some boost pads or somesuch to bring it into relevance.
Absolutely no reason to go here since it's slow and has nothing in it. Maybe add a powerup or two so that it's at least less awful to get pushed down?
This one again. The tunnel route is now very neglected, since it is slower for almost all cars than the normal route while also offering no pickups whatsoever. It doesn't need boost pads, since it's not catastrophically far behind the pace (and is possibly a better route for Tempest) but it could use some pickups, possibly one set at the entrance to the tunnel and one set at the exit?
As an aside, I've been getting the suspicion that there's something quite wrong ever since the physics changes in 1.2.7. Specifically, landings on tracks with rough terrain like Alhatra, Yuri and FIC have become very nasty. Though the 'sharp' bounces or hard stops that used to be a big issue are now much reduced, the cars have started to 'slide'/grind along on landing, as if the wheels are being held off the ground by the car body making it unsteerable. It's very hard to point out and I'm still not entirely convinced I'm not imagining it, but I swear this is something that didn't happen before, and can make things even more inconsistent than they used to be.