Hello everyone,
With my LvL 20 (Veteran) I died several times on the walkway to the ship and then timed my last death so that I could revive myself on the ship. I only pressed the revive button when the ship had set off and felt like it was 5 or 6 meters away from the dock. I was then revived on the ship and taken to Kul Tiras. Once you get there you just have to jump off the ship early enough to avoid being attacked in the harbor.
I don't know if this style works for pure F2P, but I would expect it to. The area is basically accessible to F2P players.
What I would like to say is that in my opinion this effort was not worth it. After I had gone through the entire horde area and killed all the rare enemies, I had an item level of around 57. There was no real improvement from going through Kul Tiras. This may well be different for another class. I did this task with a druid and he was able to exchange maybe 2 or 3 items for a socket for gemstones.
However, these stones only provide 2 stamina and 2 mobility per gem socket.
As already mentioned, it may be different with other classes, but I got through the Iron Docks instance just fine with the existing item level. It was close here and there, but that's part of it. In addition, you have difficulty moving around there. You have no flight points, you can't fly... it took me a few hours to complete everything.
If I were to do a level 20 character again, I would use the time to get easy-to-get items like the Raven Heart head of Shirrak from the Auchenai. This is the first boss in the instance, back and forth in stealth mode as a druid and killing the boss took less than 5 minutes. At some point after 4 or 5 attempts the head with 3 sockets dropped. You don't have to rely on luck as to whether it will drop or whether it will drop with sockets.
As I said, this may not be possible for cloth healers etc., but it worked so well for my paladin and the druid.
I would therefore recommend saving yourself Kul Tiras and rather see where you can quickly and safely get the two or three slots that you are still missing in BC instances.
Ultimately, all blue items are just a means to an end and not endgear, right? And if you have all the blue-items from the Horde area, that should be enough for your first solo instances.
As I said, I'm not a professional in this matter. These are just my experiences with 2 characters (Paladin, Druid) and the resulting opinion.