No employer contract, what IP rights do I have?

Ive been employeed by an Advertising agency for coming up on 3 years now as a web developer. Prior to my employment I was a subcontractor hired by this same agency for about 3 years. I have had many frustrations with how the company is ran and I am planning to leave in 10 months. The most striking thing to me is I have never signed a single document, contact, etc.

I still have hopes in working with this agency again on a subcontract basis after my employment.

I just got done reading the excellent post here and I am left wondering a couple of things with regards to IP and proper exiting etiquette.

1. Seeing as how I did not sign anything, I should be able to compete with this agency after my employment?
2. Prior to my employment, would I own the rights to all the software developed as a sub contractor? I assume I could prove this by emails and when the sites went live.
3. During my employment, would I own the rights to all the software I developed?
4. During my employment, would I own the rights to all the software I developed in my spare time? Judging on that other great post, I do own the rights. How does that work with overtime or times I have taken the work home with me?
5. If I have the rights for the code I wrote prior to employment and / or code during my employment, if they wish to re-use this code / modules on futures sites, do I have any recourse?
6. What is the proper notification time to let the employer know you are moving on? I was originally thinking one month, which is twice as long as the typical two weeks. I am still interested in working with them immediately after my employment so I feel as if that justifies a shorter notification time.
7. I don't know what is typically in an employee contract, but is there anything else you can think of that is / isn't in my favor?

I realize this is potential legal advice which I would always consult with a lawyer should the situation arise. At this point in time I am trying to figure out ahead of time what to be on the look out for and how to protect my interests. Its amazing to me this agency has been around 45 years without signing any legal documents with clients or employees.

Thanks in advance for any help / guidance you may be able to provide. I greatly appreciate it!

Q1. Seeing as how I did not sign anything, I should be able to compete
with this agency after my employment?

Yes. If you haven't signed anything that limits you, you are free to do what you want.

Q2. Prior to my employment, would I own the rights to all the
software developed as a sub contractor? I assume I could prove this
by emails and when the sites went live.

That depends. Independent contractors own the rights to the software they develop unless there is a contract that says that the person paying you owns it. If there is no such agreement then you own it.

Q3. During my employment, would I own the rights to all the software
I developed?

No. The employer owns all rights to what you develop as an employee.

Q4. During my employment, would I own the rights to all the software
I developed in my spare time? Judging on that other great post, I do
own the rights. How does that work with overtime or times I have
taken the work home with me?

That gets complicated. IF it is different from your employment then probably yes, but if it is similar to your employment then maybe not.

Q5. If I have the rights for the code I wrote prior to employment
and / or code during my employment, if they wish to re-use this code
/ modules on futures sites, do I have any recourse?

If you own it, then you would have legal rights. Having the financial ability to defend those rights is a very important factor.

Q6. What is the proper notification time to let the employer know
you are moving on? I was originally thinking one month, which is
twice as long as the typical two weeks. I am still interested in
working with them immediately after my employment so I feel as if
that justifies a shorter notification time.

Most employment is at will, meaning you can leave without any notice. Practically, you should give two-weeks notice to maintain good relations.

Q7. I don't know what is typically in an employee contract, but is
there anything else you can think of that is / isn't in my favor?

Not having signed a contract is in your favor because employment contracts generally place restrictions that favor the employer.