Back up sdcard to cloud
If your device is rooted, you might want to take a look at Titanium Backup, which has built-in support for Dropbox, Box and Google drive.

As for your "special folder", I'd say you will probably like FTPSyncX -- which allows you automatically sync with Dropbox as well as with your local PC via SSH, FTP, and others. The latter can happen automatically all xx Minutes when your Wifi is in reach, or when any Wifi is in reach, or generally... And the App is well supported. Alternatively, there is FolderSync, additionally offering support for SkyDrive, SugarSync, Ubuntu One, Box.net, LiveDrive, Google Drive, Google Docs, HiDrive, NetDocuments, Amazon S3 and WebDAV.

FTPSyncX:

 

FolderSync: