External wallets are possible, but you need to import your existing wallet seed phrase into OceanX. OceanX does not support browser extension wallet connections at launch.
Yes. OceanX supports one click execution using session based embedded wallet signing. You authorize trades up front within limits you define. See Wallets & Security.
Not for routine trades within your session limits. Session authorization lets your embedded wallet sign automatically within parameters you set. You can revoke this at any time.