Your problem is you do it all wrong.
If you wanna chest, you pick a champion that doesn't get played often and play him/her in uncommon role. Like Viktor support, Kennen jungle or AP Blitz mid. There are few other tricks how to make the chance of getting S but I am sure you can google them out for yourself.
Now keys are different matter. They were made to be unfrequent, especially for grinders out there, to make sure many people will get so frustrated with their 10 unopened chests that they will eventually buy some keys for RP.
If you have 10 keys, you're one lucky sodoma bleach, and I envy you :-D I play solo-with team about 50:50, I don't play often but usually I have about 6+ unopened chests sitting in my inventory.
And no, you can't send the keys to your friend. That would make Riot lose potential money so it will never be possible. Same goes for crates exchange. Don't even think about it, or Tencent enforcers would come to oyur house and beat those silly ideas out of your head with your own dog :-))))