Hi guys!
Yet again, it was time for me to risk life, limb and game for you so
beatdoc16 and I could test compatibility of sims and houses transferred between World Adventures and the TS3 base game. My base game is fully patched to the newest patch, whatever the version number is currently on 4th Dec '09, so any results below should take that into account. For example, if my game were not patched the result may have been a game crash when a house with a basement was installed. But the latest patch allows for houses with basements in the base game so the patch could be the reason behind the positive results.
Teh rezultz:
1. WA-packaged sim and house with base game content imported into base game. Both came to me as Sims3Pack files.
I use the Launcher to put content into my game, so I have no idea what result you would get with the custom installer from MTS or Simlogical or wherever it is.
Sim - complete success. No warnings of any sort. The sim came with
beatdoc16's default eyes. I would probably not have noticed this had I not recently switched defaults so I have different ones than she does. We used to have the same default eyes. Anyway, I don't know what the result would have been had the sim come as a .sim file and not a Sims3Pack, whether my defaults or
beatdoc16's would have been showing. Also, as I did not keep playing the sim beyond placing her on a lot and getting her to read a book, I have no idea what the genetic implications would be of the sim coming across with the custom eye textures. Since there are no truly custom eyes in this game, it's possible that the game would have ignored the custom texture or it could be that the sim may have had kids with the custom eye texture. When I get a bit more time to muck around with the game I might play this sim a bit and get her knocked up and popping out some kids to take a look at their eye genetics.
House - no problem, no warnings, seemed to function fine.
2. WA-packaged sim and house with WA content imported into base game. Both came to me as Sims3Pack files; installed using the Launcher.
The launcher gave me the good old triangular sign with an exclamation mark in it in the Status box. I decided to brave it and selected to install both. And both installed without problem.
Sim - got stripped of WA content. I'm not sure how much WA content she was wearing, but I'm pretty sure she ended up with totally different hair and clothes than in the thumbnail. Also, unlike her twin with no WA content, she was showing my default eye textures and not
beatdoc16's. No errors, etc, only the warning sign in the Launcher prior to successful installation. I only placed her on a lot so I have no idea whether they would be weirdness if I kept playing her, but she placed fine and perfomed basic functions such as reading a book without problems.
House - did NOT get stripped of WA content. The house came to me with a WA wall which was not located anywhere in my build catalogue. So at least walls transfer across with the house. I'm not sure if
beatdoc16 included any other content but she had pre-warned me about the wall being included so I looked for it. It was there. Proof:

I later looked and the wall did not install into my game. It is not in the build catalogue but only exists in this version of the house. I did not try using the eyedropper to recolour other walls using the pattern. I suspect that, like the custom sliders, I would lose the wall. Or possibly crash.
I am quite happy to continue testing so if anyone would like to send me a house with a WA floor and another one that includes a specific piece of WA furniture I would be more than happy to install them and test them. Can I have one with a bed and a separate one with something quite specific like an Egyptian statue or the scooter from the transport category? ie. one that is easily substituted by the game and one that is more tricky, such as a scooter. And can I have a picture of the bed/statue/whatever so I know what I'm looking for? I don't play the game often enough to recognise whether a particular bed came with the base game or is EP-specific. I only know the basic base game iron bed, but none of the others. My sims tend to be dirt poor for a long time. LOL
I will continue to test this house but for now, I declare both sim and house transfer from WA to base game a resounding success and safe! Unless some of the buy mode stuff causes problems. But just putting in EP-specific walls and hair/clothing made no difference. The patched base game coped with them just fine.