Which regime after auto-entrepreneur?

I am an auto-entrepreneur operating a renovation service, since 2009. I have extensive decennal plus public liablity insurance. Any elements for which I’m not insured, i.e. electrics, plumbing and other specialist trades need organising externally. It would be more efficient in many circumstances to sub-contract, which I obviously can’t do under current conditions. Add to this my vehicle insurance, mileage, professional training initiatives, possibly an accountant (as I want to apply for finance from the bank, and they need official bilans) and you begin to get the picture. Nearly a quarter of my allowed turnover for services is eaten straight away by fixed charges. Clearly, in order to grow the business efficiently it’s time to evolve, so I’m looking for a bit of advice to get me focussed on the possibilities.

Which is the simplest and least costly regime fiscal within which I can deduct allowable expenses with no ceiling to my turnover? If I want to draw a minimum salary, does this get subtracted from the net profit liable to 46% social charges, i.e. is it an expense / frais? I have seen you write about a €3000 sum for 1st year social charges, payable trimesterly, presumably that is €3000 spread over each trimester, so around €750 a time? If I want to ultimately move on to creat an EURL or SARL with partners, is there any step I should carefully avoid at this stage?