How does an auto-entrepreneur register multiple activities?

We have been living in France full time for six months and have opportunities to earn some income to top up my police pension. Firstly we have a gîte which has never been used as a business and we will look to start perhaps in summer 2016. Secondly I have been working as casual labour for a friend who has a business maintaining homes here owned by Brits. Thirdly, my wife and I are interested in starting a small business making and selling fudge in local markets.

Some time ago I tried to register as auto-entrepreneur as a house and garden maintenance guy. However, that particular option appears to have been removed from the list which caused me to pause (and register with this site). I watched you video about registering and it made it very simple to register as a gîte owner which seemed a good option as eventually we will be doing just that. I did not register my wife, just myself.

I now have received correspondence and the numbers I need as a registered person. However, friends have advised that registering as a gîte owner and working as a maintenance man are not compatible activities and will cause me problems.

1. Should I remain registered as a gîte owner even though this will not actually earn any money for the next 18 months? If not how do I undo that?
2. Can I register a second or separate activity as a maintenance man, and will that result in changes to my siret numbers ? (My friend cannot pay me without the correct numbers for his own paperwork).
3. Can I also register as a maker of fudge and a seller of fudge, or should my wife register those activities?