[pushkins]

Not knowing your soil type makes this a little more difficult, the frost line code being at 48" and your footing only being down 34" is likely to be a sticking point with any inspector but you may well find that he/she will allow this to be grandfathered in.
At 18" and 8" deep the footer should be able to support a second level, again soil type is very important.

I doubt you will ever find someone with an "OK" stamp that they will loan you sight unseen.....(if you do....let me know....lol).

An engineer will most definitely be able to evaluate your conditions and give you a nice little stamp on your plans when he/she has approved them. Once the engineer signs and stamps the plans no matter what the city inspector says the engineer will be right, cause he/she has liability insurance that says his right....lol.

You are going to need plans drawn, my suggestion would be to get them drawn and then submit them to an engineer for approval, most architects have an engineer that they often work with and I'd expect you will have to pay around $250 for the plan evaluation.