Multi-lingual buttons is an area where we know we need to fix. Your honestly the first to ask us to fix it and we're surprised others haven't. Part of the reason, we believe, is because the icon logo (just the 'f') is so recognizable. Similarly with the other logo buttons without any text. With that said:
1) No, right now, there's no text-type buttons built-in to JFBConnect that you can use...
2) Yes! There are multiple ways to do this:
a) If you're using the SCLogin module or any of the auto-added buttons (like to the Joomla or EasySocial registration pages), you can use your own custom buttons. To add new buttons, add them to the /media/sourcecoast/images/provider/<social_network>/ directory. In there are already icon.png and button.png. You can add as many other options as you want. Then, in the JFBConnect -> Configuration -> Facebook area, you can set the default that's used for any auto-added buttons. In the SCLogin module, you can also select your own custom button that you've uploaded.
b) You can easily create your own links:
<a href="javascript:void(0)" onclick="jfbc.login.provider('facebook');">
<img src="/media/sourcecoast/images/provider/facebook/icon_label.png" />
</a>
You can use an img tag or text in there, or whatever else you want. That's how our tags work already.. they generated (basically) that HTML above. You can just change the jfbc.login.provider('facebook') to 'google' or 'linkedin' for any other provider
c) You can use our {JFBCLogin} tag to specify the providers and images to use:
{JFBCLogin providers=facebook,linkedin image=custom.png text=Login with}
That will show:
Login with <Facebook> <LinkedIn>
Where <Facebook> is the /media/sourcecoast/images/provider/facebook/custom.png file and LinkedIn is similar. That tag can be used anywhere you add HTML to your page (module, component, template, etc)
3) See above
4) In the Social configuration tab, there's a "Providers" input box. Just add "facebook" there and that's the only one that will show.
I hope that all helps, but if you have any questions, let me know. We have a lot of flexibility in how you can add buttons. A bit of that was added in the 6.1 release though, so it's not fully documented as well as we'd like.
Alex