Fixing the page order with the editor is tedious to say the least. There is a plugin to help with this but of course we can't upload it to wordpress.com.
My suggestions are:
1) include the page order widget in the standard ones for wordpress.com blogs. In case there is any doubt, this is it's page. I have tried this out and it seems to be a great little plug-in. This would be a great solution IMHO.
2) include the order field (maybe as an option like author is for example) in the list of pages so at least we can see what it's set to, and make sure the pages display in the order the average template will display them in . At least it would then be easy see which numbers need changing.