I'd also mention joining IPSE (http://www.ipse.co.uk/) which a is trade organisation for freelancers. They provide various benefits including IR35 insurance that covers investigations.
Freeagent is a good online accounts package as well, but you need to find an accountant that uses it.
One other thing I would say is that I'm not sure your points about IR35 are correct. EG:
* Don't use equipment provided by the client;
-- This would be very hard to do. Most clients I've ever worked for supply you with a PC to use and won't allow non-corporate devices on their network.
* Be careful with paid-for meals or participating in company parties.
-- Never heard this mentioned before.
* Avoid working for one client for longer than a year when possible.
-- A lot of cients will enforce a maximum period of 2 years anyway, as after that you could theoretically claim benefits.
There are a lot of scare stories propogated about IR35, and a lot of it is by companies that sell IR35 Contract Reviews, IR35 Insurance etc. The number of IR35 investigations each year is in the low thousands, and there are 1.8m contractors in the UK.
Re. IR35 investigations - that number is going to go up. The new intermediaries legislation will give HMRC a ready-made list of likely targets. I expect the first people to be hit will be in companies with a large number of contractors supplied through the same company.
Freeagent is a good online accounts package as well, but you need to find an accountant that uses it.