I thought you may have lengthened the track massively. Driving this in a BMW 320i Touring Car with less than 300bhp, it felt like a very long track! But I've looked up the length and it is 4.8km so you must have the scale about right.
Track width good, smooth, slight camber here and there as a street circuit should have.
Perfectly square 90° corners. Metal barriers overshoot towards the track to pinch the available space to match the real track. How did you do this - it's amazing! I haven't seen such sharp apex points on another track. The tangled inside barriers prevent corner cutting. Magic.
A few bits of scenery help orient the driver. Would you consider using dirt banks or tree lines? They hide the rolling scenery so a driver can imagine it's a crowded street track, with tall buildings casting shadows either side of noon.
I might look into the surrounding scenery as you requested mate.
As for the 90 degree curves had to used a modded apk.