Bro, maybe you should open a similar thread in Property Talk to help fellow homeowners. One question, my new condo is going to be ready soon, from your point of view, what are the things I need to look out for, i.e. areas that construction companies / developers can skip on or most likely to have problem with?

Workmanship is what you are willing to pay for it. There are Premier League players and there are Conference players, both is paid differently because their skills are very different.

You should go and get a few quotation, but I think when you involve hacking / wet works especially piping, the job scope is enlarged and becomes more complicated immediately.

I think you need to at least submit your plan for approval, as otherwise they can later deem your structure illegal / unsound and you kena..

Approval is usually dependent on the safety of the structure. Should not be hard to get, but it might take a while depending on the speed of the worker.

Songlap wise, it probably help speed the process up rather than get it approved. You can also use a runner to help speed it up.