NavigatorNY said:

Suppose I am blockaded. What do I click, do I send offense or defense, to whom, how?

IMO, first of all, decide if it's worth it. If you're not being ransomed, then being blocked equals being protected from everyone else. If someone hits your blocked haven, they hit blocker's units, not your own.

Always liberate with off, because what you're doing is attacking the blocker's units. Be ready to quickly turtle (or recall, if liberating someone else), so your off doesn't stay exposed to quick counter-attacks or Fireships (although, it's quite dumb to hit off with FSs, but people still do it).

NavigatorNY said:

Do I just go to Pirate Stronghold and click Recall and click All Offense to send it all to the haven to fight off the enemy?

No, you'll have attacker's icon and a menu over your Stronghold, similar to those that you see when you enter any other blocked haven. That menu will have a "Liberate" option, just like those menus in other blocked havens.

If you see the incoming block, and you know they usually send strong off, it can be a good idea to recall your own off from the harbour 13-14 sec (but not 15 sec!!!) before they hit. Your off will take 15 sec to arrive to the Stronghold, i.e., it'll be there 1-2 sec after the hit. Then liberate, before the attacker's def arrives, and even before they manage to recall their off, cause them massive losses (because it will be your attacking off against their defending off).

A similar timing can be done with off from another account, but it's not likely you'll get a chance, since everyone charts their real attacks.

NavigatorNY said:

And if you lose units fighting off a blockade, do they still come back to you in the Infirmary?

Yes. Infirmary gives you free revival of your own units that died in your own haven.