Your second point appears to confuse the GUF2 with the Amex 241.

You get a GUF2 at 2,500 tier points and (now) two GUF1s at 3,500. So you could book four J redemption tickets and use all three GUFs to upgrade to F, deploying one joker if required; cost 400,000 avios. LTN is correct, a joker releases up to five seats, one for the GGL and up to four for travel companions on the same ticket.

Then get a BA Amex...