You need to inform your insurance company of any material change to your circumstances.
You need to keep it insured for fire or theft.
If it's still got tax left on it, I'm not sure you can get that back if you SORN it?
Yeah if it's declared sorn he will get any tax that's been paid already back as long as it is more than a month (they only refund full months). Dvla automatically refund once you have delaclared it sorn.
Make sure if it's sorn you don't keep it on the road or even parked on the footpath as it can then be clamped and taken as it is not classed as off road
generally when it comes to anything with motorcycles it is a small community, try and get people to spread the word, example stuff for free? make videos? Market it i suppose, what would make someone go to your store instead of the one next door or why not go online...