1/ Yes, it COULD. Try it to measure the impact.
2/ Yes, the indicator should look a little better.
3/ I don’t know how is computed the RACH success rate, so I don’t know if this feature could help regarding this specific indicator
4/ Yes. How ? By slowing down the repetition of the Channel Request, hence giving a higher probability that at the second or third attempt, the SDCCH channel is free.