I'm in love & I want to get married; but my partner has a checkered financial past & I want to protect myself?

I have worked very hard to get to where I am, graduated college a few years back with two degrees, worked throughout - have great credit and no debt other than finishing up with student loans. I have my own business, and while I don't make a lot of money it's enough for both of us to live on so we have been living together for about a year and a half.

During that time I have been paying all the bills and rent so that she could start repairing her credit and collections from a few years of irresponsible living beyond her means in early 20s. Her car even got repossessed at one point before we moved in together, but she has been doing great since and we've managed to live well though very meagerly. We have bought a car together with both names on the title which I didn't mind doing even though we did not contribute equally (I paid about 90% so she could save to take care of debts) and I cover all car insurance premiums with both our names on it. I love her very much and we have a baby son together, she has been staying home to take care of him and went to working only part time as she loves being a mom and finds her job not satisfying. We have a joint checking account which we share for groceries that I put a certain amount of money in and then each of us is free to use the funds for food however we want as long as we stay within budget. It has worked out pretty well, but there is one big thing that I'm still very reluctant to share and that is ownership of the house I bought while we were living together. It's an investment property as well as our primary residence, and I've become the property manager.

After living together for almost a year, a situation came up where I was able to purchase the multi unit building we lived in and we talked it over and so I did back about 8 months ago (my name only on mortgage and deed) with considerable loan from parent to help with down payment that I will eventually need to repay.

I don't want to have to have a prenup when I ask her to marry me, as I believe we have a strong family right now and can't see myself ever wanting to be with anyone other than her - we have a beautiful son together and I know she wants to get married at some point as do I. it's obviously not the most romantic way to go about things either, and I could see how having a prenup written up could be viewed as planning for our relationship to fail which I don't want her to think I am doing. Still, she like most people is no saint - has had emotional problems that affected our relationship early on and problems with alcohol in the past (which we've also talked about) so while things are great now I really can't predict how things will be in 20 years. At one low point I made it known to her that if she continued to choose alcohol over me then that would mean the end of us, and thats the way I still feel especially when I think of our young son. Anyways, I don't want to give the wrong impression and I feel a bit silly even writing this - she is wonderful I do view her as my life partner. But as I'm getting more serious about wanting to marry her and reading about community property law some questions keep coming up and I need answers to assure I'm doing the right thing.

1) If I bought the house before we were married, but while we still lived together within the same building I was purchasing how would the courts view that? We were cohabitating and already had our son at that point. As I said again, she has never contributed a cent to the mortgage payment and I wouldn't ask her to.

2) I never asked her to be a stay at home mom, but I realize she is sacrificing potential income to do it. She never finished college however and her job wasn't highly paid nor did she enjoy doing it full time. I think we both view the tradeoff of the traditional arrangement (man brings home the bacon, woman homemaker) a fair one...we both agree that we didn't want to send our son to childcare and to this day no one has watched but one of us or a family member. But I still wonder if the courts would view her "income sacrifice" as a reason to warrant giving her partial ownership of the house (even though if we worked out the numbers I'm fairly certain she's better off both financially and emotionally under this arrangement than if she worked full time and we had to split the cost of living that I now cover such as childcare / food)?

3) Once we were married I believe we have joint credit, since hers is way below mine (which is about 780) what would that do to my credit rating. My plan is to eventually get our family out of the multifamily into something with more space and privacy, but still hold on to that investment property as a side business. So within a few years I will be looking at getting another house (possibly with both of our names on depending on circumstances - I'm open to it and in no way against owning property together if.) We've been making her payments to get her cred