Hi there and welcome to the boards
There is a FAQ section with a lot of info about PUPD which you may find helpful -
https://babywhispererforums.com/index.php?topic=275699.0In response to your first question - yes I would leave LO standing until they cry, if happy or just messing about then let them get on with it, only really intervening when necessary.
The second is a little trickier for me to answer without a bit more information - I hope that's ok to ask a few questions? What was the reason for you starting PUPD to begin with? How was your LO previously falling asleep? Usually with PUPD at this age you would tend to put LO down and be 'hands off' - certainly if you are trying to get rid of a prop you don't want to create a new one of LO expecting your hand on them to go to sleep. But if you were (for example) previously holding to sleep then you could possibly have a hand on as part of a process of gradual withdrawal, with the aim of eventually not needing that either. In general though the idea is that LO does the falling asleep on their own so I would aim to be doing the minimum needed and probably try to keep hands off as much as possible.
Does that help?