APE code for gardener and garden maintenance in France?

I have been working in France since August 2010 as a part-time gardener (cutting lawns, hedges.) for people with holiday homes and will work around 140 hours this year. When I registered as an auto-entrepreneur business I was given the APE Code 81.30Z - Services d’aménagement paysager as a professional liberale. I am coming to the conclusion that this is not the correct code as it seems to suggest I am a professional landscape gardener. I have contacted my the RSI and the MSA about business cotisation payments and the conclusion is that I have been placed under MSA and classified in the same group as a farmer.

Should I have been placed under the MSA umbrella as I don’t work enough hours to benefit at all from their scheme? I still pay cotisations each trimestrelle to CIPAV as an auto-entrepreneur but if I were to work over 150 hours I would have to pay MSA 900 euros. Should I be paying cotisations to both CIPAV and MSA?

In the future I am taking on decorating and handyman work which is not covered by my current APE code and I will need to switch codes. The most appropriate one is 9609Z which is under the artisan category. If I were to switch from prof. liberale to artisan what are the implications? What would happen to the cotisations I have paid so far?

My wife has been offered a cleaning job in France by a friend and is wondering if setting up as an auto-entrepreneur is the best regime to join. She is hoping to take on more jobs in the future. Is it wise to set up as an auto entrepreneur when you would initially only have one customer?