http://community.elgg.org/plugins/384766/3.0/loginredirector

You can set up where users should get redirected to after login with a separate choice for the redirect after the first login.

Topbar icon is a menu item, you have to unregister the default and register a new with your preferred icon size.

elgg_unregister_menu_item('topbar', 'profile');

Do this in the plugin where you keep your changes, http://docs.elgg.org/wiki/Dont_Modify_Core

Settings are different for each widget - some widgets simply have a single setting of "how many to display?" and access.  Some might simply have access and nothing else.

The widgets you've mentioned sound like they're operating correctly.

I'm not sure if I understand you're problem correctly: can't you set the widgets options being shown or are you missing options you see on some widgets at other places? In case you can't set the options shown (for example number of items to display or access level) this surely is not how it should be. In this case maybe the theme you are using on your site (or some other plugin) is causing the trouble. In case you miss some options available for some widgets at other widgets: as Matt said, the different widgets might have simply different options. Often you can set the access level or the number of items to be displayed. Other options are more specific to a widget and wouldn't make sense on other widgets.

Thanks for your help. Yes, the problem is that the options shown can't be set by the user. For the user, on their profile page, all the options for the widget are there -- ie, 'how many to display' etc -- but there's no way to edit them. There aren't any dropdown selects or text fields to enter a number in. For instance, in the Friends widget it says, 'Icon size' but there's no way to select small, tiny, medium, etc or to enter a value.

I'm not using any theme plugins. I'm just using the standard profile 1.8 editor. Any ideas what could be causing it or how to troubleshoot it?

Thanks again for your help.