Questions I cannot Find Answers For

Thanks for all the wonderful tutorials and whatnot on this site, it really started me in flash a few years ago, and I’m now back to learn about gaming.

The guides have been so nice to see the actionscripting behind these games, however I do have a few questions concerning some of the ways that these are built.

[]In creating an RPG, if you have the likes of 30 or more different tiles, it it worth it to create it based on the tiling system shown in the tutorials. Or is there a different way to compile a map using this method?
]Is there any size limitations regarding maps, characters in scenes, items, etc that you might have encountered?
]If my character walks into a building I understand from my reading that this is a second matrix to display the inside. How does this affect large maps, are there more effective ways to program this?
]Is there a way to use a random placement for items in a scene based on certain tiles. (ex: coins under bushes)?
[/list] I’m starting my planning and want to make sure I’m on the right track. While I’ve used flash for POP displays, I have not done Game Programming before. Any help or links to additional threads would be great. Thanks in advance