wife wants to become Sole Trader, I'm PAYE.

Hi there,
my wife wishes to become a Sole Trader and sell a home made product. From searching through the boards I came across a situation where a wife started a small business but Revenue allocated her, her husbands PPS number for the business as he was the main earner and they were jointly assessed.
At the moment my wife doesn't work so I have her credits. There are two reasons why she wants to get the business up in her name (apart from making a few quid).
Firstly, we are assuming that we will then be assessed with the higher cut off for higher rate tax as she will be working.
Secondly, the house is in my name and so if she, God forbid, poisons someone or goes broke owing revenue a sum, I want to make sure the house is protected and that she is only liable for whatever is in her business account and it doesn't come back on the main family income.
Does anyone know if there is a risk of my assests if she is the Sole Trader but using my PPS?
What would complicate things even further (how, says you), is that as a home business, I'll be roped into helping every now and then so I couldn't put my hand on my heart if it came to it and say I didn't have a part in the manufacture of the products but would not be an employee.
The only other option open to us is opening a company but I can't see her earning more than circa €7K pa so by the time we have all the legal fees paid, we could be down 30% of her profits.

Any tips. Legal ones preferably. .
FJ.