Hi,
You can publish items on multiple pages (as shown in this video) and there is also a way to do it in layout.master so that an item appears on all pages without having to publish it on all pages, see this thread.
mojoPortal is under very active development and I am of the release early release often philosophy so I would check back frequently or subscribe to the blog. Of course its up to you if you want to upgrade every time a new release is made.
Generally I recommend always update everything to make sure you don't miss any important changes. For example you should never try to keep your old Web.config file because you may end up missing some settings. Instead, you can put most of your Web.config customizations in a user.config file as indicated in this article, and this makes it less painful to upgrade Web.config.
I have some recommendations about uploading files here and some other tips about upgrading here.
The next release is mostly new skins but there were plumbing changes needed to support some of the new designs so its best to upgrade everything even on this coming release.
Hope it helps,
Joe