Oh man f[r]oggy I feel for the dude. What a shitty situation.
HEre's what struck me out of your post:

Quote Originally Posted by TheGreenFog
Tom felt she was always bringing up the marriage issue ....This would cause them to argue frequently. She said that if she was married that she would not have anything else to argue about.
That's quite frankly BS because there are ALWAYS things to argue about in a relationship, if a part of a couple's poor communication is arguments.
That isn't going to change until the communication changes. Only the topic of the arguments will change.

Quote Originally Posted by TheGreenFog
A month or two went by, and Tom wanted to buy a house. .....she was not ready to go into a house with someone she was not married to. Tom was not ready yet.
The house thing- been there, and it pretty much put the nail in the coffin of THAT relationship! I want to be married for legal reasons when I buy a house with a partner- and I asked myself, am I ready to marry this guy? the answer was no... and then the question was, will I ever? Nope! End of story.

Quote Originally Posted by TheGreenFog
.... Tom had hurt her on a couple occasions during their relationship by talking to other women. .....he did enough to hurt her and to make her consider leaving him. She stayed anyway.......She also wanted the respect of being a wife instead of a "girlfriend."
Man I can see where she is coming from- I get that feeling too, that once you get to a certain age it seems silly talking about your boyfriend, lol! BUT an educated and logical woman should see that the RESPECT bit is kind of Victorian... we should be over that by now! And if the title means that much, you have to ask WHY? Labels can be used to compensate for insecurity... does she need to feel validated by the title of 'wife'?
Also 'talking to other women'... !!! f'real?
And the last bit of this... the combination of the insecurity and the need for a title... by labelling Tom as her husband, and putting that ring on his finger, I would HOPE she isn't trying to essentially piss on the fire hydrant and claim ownership of him in a visible way that would make him less able to talk with other women (although it's a known fact that married men get hit on just as much as, or more than, single dudes!).

Quote Originally Posted by TheGreenFog
but he said that he felt pressured throughout most of the relationship, and that he never really got a chance to "feel" it. The only way for him to get her back is to ask her to marry him.
And that's not a good reason to get married. Someone close to me went through that already. And is now divorced and it isn't a pretty scene.

The bottom line is that a proposal is not going to help. If she is as smart as she sounds to have a good career and all, she will on some level KNOW that she pressured 'Tom' into this decision and it's going to make her feel like shit, and question whether he really loves her, or if he married her out of a sense of obligation. The arguments are going to change to: "You don't really love me, you only married me for xxxxx reason!" (insert self-pity here)

It sounds like the relationship is already committed enough to justify a few trips to a marriage counselor.