Nobody should use EWallets. Casual users might use lightweight nodes, preferably with fraud proofs (which don't exist yet, but hopefully will in a couple of years). As many people as possible should use their own independent full nodes -- certainly anyone who accepts transactions automatically.

There are several plausible ways that full nodes could be distributed securely. I've recently been thinking that it might be best for the vast majority of Bitcoin trade to move to dedicated hardware. End-users would have something like a Trezor, which would operate as a lightweight node with fraud proofs, and businesses, both online and in-person, would have dedicated Bitcoin-acceptance devices which would contain full nodes. This also helps a lot with the various security issues.

Other possibilities/ideas:

- Everyone runs a full node on all devices. This is possible with aggressive pruning.
- Most people use lightweight wallets with fraud proofs, and all merchants run independent full nodes. (Unfortunately, history has so far shown that businesses are even less likely to set up full nodes than end-users.)
- Everyone has a dedicated Bitcoin "base station" device at home which acts as a full node and something like an Electrum server, and all of their wallets connect to this device.