SARL and auto-entrepreneur at the same time?

So we’ve established an auto-entrepreneur under CIPAV is charging me 6.3% extra for sales revenue. Not good, but it’s forced me to take a fresh look at what I’m doing. As my turnover is increasing rapidly anyway, it’s not long before I’m likely to outgrow auto-entrepreneur for sales. Having spent the best part of yesterday researching I am now thinking that a SARL would be my best course of action. We are in a ZRR and I can afford to wait to take profit mainly as dividends.

1. It appears that liberale professions under an SARL are not that efficient because cotisations can still be due on dividends. This being so, can I continue with auto-entrepreneur for my consultancy work?
2. I have about 15K of stock accumulated that I have paid VAT on (thought I was being clever beating the UK VAT increase for sales under auto-entrepreneur). How can this be treated if I move to an SARL, it seems unlikely that I can now get the (UK) VAT back, although some suppliers might be prepared to re invoice me later perhaps. Obviously I don’t want to charge VAT on top as well as not being able to claim it back.

Thus can I continue to sell existing stock off under auto-entrepreneur and use the SARL for new stock and other products? Both of the above if possible would also help with the transition to taking only dividends next year.