Hopefully yes. For a vault (farming), the communications is likely to be the limit not CPU. A client (user) will have more CPU load because it is doing encryption and decryption.
You should be able to test this soon, maybe this week or next - watch for the weekly “Dev Update” post which usually goes up late on Tuesday’s. Can’t guarantee Pi (ARM) support will be in there, but fingers crossed.
There won’t be a Safecoin wallet until the network leaves testing, but in the meantime MaidSafecoin (a proxy token) can be bought on exchanges such as Poloniex and stored in the Omniwallet (at any bitcoin address for which you hold the private key), pending transfer to SAFEnetwork and conversion to Safecoin.
Oh, and welcome! :