Is Crux35 V2 3.5" Analog Quad good for beginner MultiGP racing ? If not, which one in similar price range available right away..

I don't have a good answer for that, but I do have an hdzero crux35 and I looooove it

Light, agile, good flight times, good default tune (analog version) only down side is you may break something in a hard crash and motors not super durable either. If you are only looking at BNFs, its probably one of the cheapest options and you can get two of them for the price of others so you would have a backup.
I don't race, I have other builds that fly faster, but the Crux easily wins in ease/precision of control so imagine it would be good for a beginner racer as being able to consistently complete laps without crashing out probably will be key for starting out.

there isnt something like a beginner race quad, as we can set a throttle limit or limit the acceleration, we can use a common 5inch race quad and make it beginner friendly.

the crux might be fun to race, it wouldnt be my choice.

Racing is a different animal and first step I would suggest is hanging out in the pits(if possible) and listen to the chatter about what to avoid and what has been working.
 There will be some racers glad to share their experience.
 

  Five33 is probably the most used frame. I have heard the tiny trainer is a good start for practicing racing.