Our current official converters require database access, so there isn't any for proboards.
However, there is another converter, a crawler of pages, which is available: http://www.simplemachines.org/community/index.php?topic=188741.0
Sorry for overquoting, it's easier to answer you this way ... :
Does the SMF admincp have a way to ban users? With proboards we have several options for banning... IP ban, email ban, and username ban... are those options available with SMF?
Of course. All of them.
Also, are there any mods to have sidetables or to shrink the width of the forum tables a bit, so that they don't stretch the whole page?
You can alter the design by installing predefined themes (http://custom.simplemachines.org/themes/
), or by manually editing the files of the forum. (you can see in the Graphics and Templates
board other discussions about how to alter looks manually)
Can I add extra scripts to the forum?
I suppose modifications (http://custom.simplemachines.org/mods/
), or extra-pages of your own? Yes.
And, is it possible to enable guest-posting on some boards but not others?
Yes, permissions can be fine-tuned for each board, so forbidden for some (with permissions profiles on SMF 2.0).
I think it's fine.
If you need to edit manually the files, you'll have php files to edit. Generally the instructions are clear though.
No need to be sorry for questions! And welcome around!