hi chris... i don't know much about this but i think i know just enough to put your mind at ease. the compatibility does not refer to how the solution is deployed (local vs hosted/server), but rather it refers to whether the script is called by a client or scheduled to run on the server. if you are simply taking an existing solution and hosting it on a server, then you will have no problem. you would actually need to intentionally set up or "schedule" specific scripts to run on the server. i am pretty sure that it makes no difference whether you are employing the data separation model or not... that is a different issue altogether. so you can host a solution using filemaker server and use script steps that are incompatible with server managed/scheduled scripts without any problem. what you cannot do, is use these incompatible script steps in a sript that is scheduled to run on the server itself. here is a link to a filemaker page about this topic: http://help.filemaker.com/app/answers/detail/a_id/6223/related/1.
the situation is a little different with iwp. in that case, if you simply publish an existing solution with scripts containing steps that are incompatible with iwp, then you will encounter problems. hope that is helpful (and correct?)!
Download a FMP trial on another computer, test the Sharing with your Filemaker Pro.
1] Pay to have the database hosted by a Filemaker Hosting Service [$20 to $50 per month]
2] Host the database on a local computer with Filemaker or Filemaker Advanced - 9 Filemaker users can access it at one time. 5 IWP users.
FMP Server [$1000] up to 250 Filemaker users access at one time | no IWP users
Whether FMPS can actually handle 250 users depends on the hardware, network, and setup.
FMP Server Advanced [$3000] no limit on FMP users | up to 100 IWP concurrent users
one other thing you may want to keep in mind in making your decision about how to deploy your solution is speed. a solution hosted on the local network will run much faster than one hosted over a wide area network such as through a filemaker hosting service. for most operations this won't be all that significant (whether something takes 0.1 seconds locally vs 0.5 seconds non-locally doesn't matter a whole lot). but if you are displaying summary data (reports or charts, for example), or displaying many records that contain calculations (conditional formatting also affects this), the difference can be enormous (e.g. 2-3 seconds vs nearly 2 minutes to load for one layout i have... it would vary greatly, of course, depending on your solution, number of records, complexity of calculations being executed, etc.). just something to keep in mind...