I have a judgement I need to collect

Yes, it can be done on a contingency, depending on how large the judgment is and who it is against. A full consultation would be necessary to...

How does a Court decide if 200 discovery requests with a declaration are too many or not?

It's impossible to predict what a judge would do. However, typically, they'll look at the contents of the discovery, the purpose of the requests,...

You can sue for breach of contract in small claims court.

Contracts/Modifcation

Depends on what the promissory note says about amendments/modifications.

Discovery requests (request for admission/production of documents/etc) can be only sent to defendants or other non-parties too?

You cannot serve discovery to non-parties. You may subpoena them for records.

Review of contract? What type of lawyer do I need?

You need a business attorney. A full consultation would be necessary to properly advise you.

Time to file a reply?

You cannot file a reply to an answer. You can file a demurrer, if applicable.

What are my options if I don't agree with a settlement amount.

As the client, you can accept or reject any settlement offer.

Can I press charges against someone forging my signature on submitted evidence in small claims months after final ruling in CA

Only the district attorney can press charges. You can report this to the police. You can appeal this decision to the Superior Court.

If a process server cannot locate the defendant of a lawsuit by serving court papers, what happens if he person trying to serve

You can be served by publication.....