I've known architects in NYC that will review the plans and provide a stamp for a set fee and have no other involvement in the project.

If so please let me know or send info on how to get involved in such group/groups.

Will they be actively involved in management or passive, earning a return based just on their investment?

Lastly, was the PM involved in you purchasing the home? 

I informed my lawyer and he said he doesnt want to be involved as bargain sales dont really protect the buyer.What are the pros and cons?

Get your lawyer involved. 

It was also disclosed in the MLS listing but everyone involved overlooked the dates.

I'm not sure what the benefit would be to have a long term and both term rental both, over having the same of each- it seems like you would have more PM overhead than would be worth it as usually PM's for STR cost more  than long term rental PMs- there's simply more work involved. 

Look up her name at the Recorder's office to see if you can find any more information or deeds filed with her on it.You could also try scanning through the articles of organization for her LLC on the SOS website.You could try truepeoplesearch or thatsthem or other online resources to see if any family members come up and repeat all these processes with them.You could also chat up your other neighbors and see if any of them know how to reach her.If you can identify a previous MLS sale, you could contact the agent and involve them in the transaction to get paid if they're able to connect you two and you end up buying the place.If you're hellbent, there's a lot of stuff you can try!

(use the search glass and look up the hundreds of conversations about it and the frustration involved).