1) Our Twitter Share modules all have a specific class around it. Try adding the following to your template to see what happens:
.Twitter.share {
text-align: center;
}Test and let me know if it helps. If not, let me know a URL where we can see the issue, and we'll gladly take a look at your page.
2) The only modules JFBConnect installs and uses in v6.x are:
JFBCSocialShare - That's the widget that shows all the share buttons like in the bottom right of this page
SCSocialWidget - It's what lets you configure all the other widgets
SCSocialStream - This is new in JFBConnect v6.1 and is what lets you create a stream of updates from different networks, as can be seen at the bottom of this site.
For the SCSocialWidget, you can either copy an existing module or click the "New" button and create a new SCSocialWidget instance. Once created (or copied) modify the settings however you need.
I hope that helps,
Alex