Sorry for short answer ...
dependencies problems are kind of good - if you were told them before you ruin your system
Instead of this graphically download manager you may try out of a console:
Switch to a folder you like the thing to get downloaded ...
if it interrupts you may try to continue
wget -c http://somesite.xxx/somesoft.xyz
downloading a full website
wget -rpkl 3 http://somewhere.xyz
Is GPG the thing you searching?
It always installas what it knows - so if you downloaded it to somewhere you would need to
Add Installations source directory (in yast)
.. or just install it by simply clicking it ...
...or by going there (to the folder) as root - and
rpm --install NAME.rpm
[rememeber [TAB] is helpfull - so when you hit N[TAB] in the directory - it tries to get all names with N in beginning letter - easy copying of some text - mark with left mouse - hit middle mouse somewhere ]