So I removed the lines from the .bat that mentioned gamma, and the game started up successfully. I guess that forced it to choose another server. Is there a better way to get the program to

I am able to use the Build/Buy function on Houseboats with AM installed just fine. Are you making sure to edit the Houseboat Lot by clicking on the Build/Buy icon in the menu with testingcheatsenabled? (This will activate the Build/Buy function as it is greyed out by default).  You will need to do this so that you can edit a houseboat lot and make any changes you want to the existing structure. There are several tutorials on the official Sims3 site as well as Carl's Sims3 Guide.

I can build on houseboats just fine.  I just had to disable the alwaysbuildbuyhere option.  With this enabled, selecting build or buy would default to the dock, turning that option off it defaults to the houseboat which is the home lot.  Also, if you are trying to edit a houseboat in the new isla paradisio (or whatever) hood, then you may need to unlock the lot to allow editing as I believe EAxis locked them all to prevent editing.

On another note, is anyone else having problems with auto grouping?  I have enabled the option to prevent the auto grouping, but whenever my sim calls someone and invites them over, they either auto group, or auto date, very annoying.

Ok possible bug. In my config I have it set up to where it is build/buy on current lot always. And when I was testing out the new 1.55 version with my config file set that way it made it to where I could not build/buy at all on houseboats. I didn't notice a problem on regular lots just houseboats. I did try moving the camera all around on the houseboat and even down to the basement and zoomed in, all with the same result the build/buy was totally disabled. No other issues found as of yet. But thought I would let you know about this one. Once I edited by config file turning off that feature I didn't have a problem with build/buy mode.