Roof to Facsia connection & soffit questions

[hollerg]

I am replacing all fascia, soffits and damaged lookouts due to rot (SE TX). [The roof is being replaced because of hurricane damage]. I am going back with wood facia and high quality prime and paint. For the soffit I am considering A-C (B-C good enough?) exterior plywood, perforated hardiplank or aluminum.

The area with horizontal fascia runs were the worst, and these runs had no subfacia. The material was some sort of OSB soffit system where the fascia had a groove.

The "books" show roof decking covers the top edge of facsia. In my case there is not full coverage. Most coverage is by the drip edge metal and the shingle cover the fascia. Is this a problem, such as at the joints in the drip edge or because the drip edge is not properly supported?

Can/should I add a subfacia and use a longer drip edge so I can support the soffit well? (hurricane wind issue) This makes the mismatch even worse by 1". If so what would I do to minimize the issue, fill it with spray can urethane foam?

Lastly, the soffit will only be nailed to the lookouts at the house end of the lookout, although I will install a frieze board. Does the lack of support preclude using any of the soffit materials?

thanks
hollerg