Your numbers are wildly wrong. Today the Ethereum chain weights 917 GB, and a year ago it weighted 456 GB. Even if you use Parity, it's still around of 400 GB.

The "plan" to deal with it has been in action for a long time already: most nodes don't have the full history anymore. They only keep a chunk of the most recent blocks, and when an operation needs a value which is not on that slice, they contact a history node to get the relevant values.
Which is not very decentralised or trustless, if you ask me.

If they're for mobile phones, wich usually don't have complete keyboard, doesn't it make sense to use a shorter TLD? A 4-letter one will be a pain to type for each site...