Alonzo-testnet current capabilities

[louazc]

Please excuse my ignorance, but I've searched and can't find the answers.
Why are Plutus example scripts provided on the "Plutus Playground"
(Starter, Vesting, Game, CrowdFunding) so different than
the examples found on the "Alonzo-testnet" (HellowWorld, AlwaysSuceeed, AlwaysFail)?
These "Alonzo-testnet" scripts are very basic and seem to only provide a script
address to accomodate cardano-cli commands.

I've tried compiling components of "CrowdFunding.hs"
on the "Alonzo-testnet" with no success.
The compiler fails on the statements like:
"import Plutus.Contract"

Is there a way to get a scripts like "CrowdFunding.hs"
on the "Alonzo-testnet"? If so, How?

Are we waiting for the complete implementation of the the
Plutus Application Backend(PAB) to have this capablity?

Will I be able to implment scripts like "CrowdFunding.hs"
after PAB is in?