Grey and Black Water Drain

Hello:

I have a Elkmont 24' and just this week we took our trailer on a fairly long camping trip. Somewhere just north of Dallas, traveling after dark on a smooth two lane road we heard a large thump like we had just run over a raccoon. We stopped looked the camper over and found nothing wrong. However, the next day at the camp site it noticed water coming out of the grey water tank...the valve had been completely broken off! Now, here are my questions:

1) Has anybody combined the grey and black water drains so you only have to hook up the drain one time when you go to dump? I know I've seen this modification on the Forum, but I've done searches and have not been able to find it. I thought since I have to replace the plumbing on the grey tank I might as well look into combining them.

2) I noted there was a very good post about going to a larger black water tank...how many people have done the switch, how happy have you been with it, and how hard was it to do? I think a larger black water tank would help us the way we camp.

3) What size plumbing/valve needs to be put on the grey water tank (any photos would help)? I have to ask this because all my grey water plumbing is lying off on the side of the road someplace and I really don't have a "go-by".

Just a side note...this trailer has a few quirks, and oddities, but it is by far the nicest travel trailers (besides a pop-up) that I've ever towed...and I've had a few over the years.

Thanks for your help.
Conrad