Appeal UK Visa-Settlement.

I lived in UK for nearly 10 years. Started with a student visa in 1998. In 2004, I applied for settlement but rejected (not refused) with the Home Office. 3 years passed by had not heard from the Home Office. I decided to withdrawn my application to go back to Thailand to re application, hope to be quicker but it was refused. I entered to the UK illegally on 2005, just because to be with my partner and unfortunately, we broke up after 6 months when I returned to the UK. 

3 years later in UK, I met a new partner and lived together for 7 months but I still kept my old flat because we were on probation of the relationships. That's why we didn't have the same address on our posts. I could change my address to where we lived together for "visas purposes" but I did not. However, I left the UK during immigration amnesty period to legalize my status in Thailand on June 2008. Of course, my application was refused again. Now I am force to appeal and it costs us money. We have invested in visa applications and 2 solicitors and the appeal is really expensive so we have decide to proceed ourselves from this website. Hope you guys could help us.

I was refused on;

1. The depth of our relationships on our testimony letter ( I think it's hard to write people feeling on paper myself) & no proofs of the same address in posts that we lived together. I am not sure that there is such a rule for fiancée visa needs to proof of the same address or council tax-change of rates that 2 people lived there? 
2. Bank statements of my partner had gone to overdraft limit twice in 6 months but for short period. He earns 3,000 pounds a month and overdraft limit was 1,900 pounds so an ECO suggested that we would seek public funds because he used the overdraft. We live in 2 bedrooms flat and we have very comfortable life. I was a manager back in UK too. I was in UK for 10 nearly years, why would I need public fund now? Can anyone suggest  how to write a letter on this matter to show them that we have finacial stable?

3. My poor immigration history, Illegal entrance, I left the UK during the immigration amnesty period. Would this amnesty apply to me too as a fiancée visa?

What I need you guys to help me to write a letter to against the decisions. If you have any suggests and comments please do so. We really appreciate anyone who would like to assist us on this important matter.

Thanks,