Hello @stewl,

Almost everything you need to do could be done right in the back-office instead of hacking code.

for example the random photo and the_rss2 and the _atom items at the bottom of the sidebar - how can I remove them?

All the elements you mentioned are widgets, and you may manage them as instructed in this page: http://b2evolution.net/man/editing-widgets. Maybe you should play around a bit by enbaling/disabling a couple of widgets before to delete them, just to identify each one of them and get used to the interface and the different options that it offers.

also, I removed the logo from the bottom right on the sidebar, and want to restore it - how?

Restore the b2evolution logo depends on how you removed it in the first place. It looks like you deleted the file powered-by-b2evolution-120t.gif from the disk, so all you need to do is restore it from the release package to the server. It is supposed to be placed in this folder: blogs/rsc/img. However, if you still need to delete it, despite we encourage you to leave it because it is a way to help promoting b2evolution (http://b2evolution.net/about/sponsoring), it does require a code hack depending on the skin that you are currently using. In the case of the page you linked, the logo section in the evoPress skin is in the file _sidebar.php.

Under the main banner on the initial page is a blue menu item "About blog A" - how do I remove it?

That is also a widget and you may find it in the Menu container at the same page I linked before.

As a side note, I realized that your site is missing some important CSS files, maybe as a product of your tests trying to modify the aspect of the main page I guess, so I recommend you to re-upload all the files to your site, just to be sure that nothing else is broken. Also, almost all the common customizations could be done by managing settings in the back-office, so try to avoid hacking code unless you need something too specific.

Regards!