To covert a tourist visa into non b you don't need staff (last time I checked). I didn't convert mine, I did get a non b visa outside Thailand and where invited of the company (which is mine) to work for the (my) company. This is how 99% does it. They changing rules all the time but this talk about come to visit your office is like 10 steps away.
First of all you need to clear the status of the company. Ask for the dbd documents and then you will see if you are a shareholder and director. Second you need to ask your lawyer what they are trying to do. Convert your tourist visa or try to to send you outside Thailand and get a non b visa.
About Samui, you don't need staff to get a work permit, the latest rule (2 month old) is that you need to register at least 1 staff for social security when renewing (renewing you do 1 year after your first wp) your workpermit.
And when you submit for social security they will probably now visit your office (1 year ago they didn't do that).
I think you need to sort the facts out and also ask some questions to your lawyer. Can they not answer them maybe it's time to go to someone else.