Can I allow my users to add new Plugins feature on their blogs

nope. Only Super Admins can. Because it’s your job to make sure they work across the network.

plugins are shared, remember. there’s one copy for everyone. If someone adds a “bad” plugin, it could take down the whole thing.

Then can I add a plugin from my end to the specific user blogs from my end If they requested me?

Thank you !

If you are the Super Admin, you can first add the plugin to the main blog or network and then login to the specific blog and activate the plugin there. Or so I believe.

Then can I add a plugin from my end to the specific user blogs from my end If they requested me?

Yes.

Thank you !