Hi Mark2007,
1.You start trading when you startselling goods or services. Registering a company does not mean that you are trading. HMRC will contact you within a week or so of registering your LTD. You can reply to this stating that you are not trading at present but that you will contact them within 3 months of starting to trade.
2. Paying dividends is certainly more tax efficient when running a company, but it should not be the sole reason for starting a company. I would recommend getting some tax advice from someone like Joyous (aka Joy) on this forum. Her website is
http://www.joyandco.co.uk/
Dividends can be paid at any period through the financial year. However, you need to be able to support this payment with evidence that the company has the funds. Keep regular up to date accounts and this is easily done.
3. I am not a specialist in Insurance so i will be of little help here. However, the company secretary is not an 'employee' unless they actually work for the company. They are an officer of the company.
If you want to discuss any of these points further do not hesitate to contact me for free advice.
Mike.