TLS on a 33 MHz m68030 is passable. Since the i80486 should be closer in performance to the m68040, negotiation could take place inside of the timeout that many servers would have. In some ways it would be a good rate limiter since you'd likely only want to allow a single connection at a time.
Nope. Anything crypto related (notably TLS transport) would not work or would be horrendously slow.