Sadly you can't transfer BA miles out to any other scheme.

However it only takes some account activity to keep them safe for another 3 years. So if you can get even 1 BA mile posted to the account the entire balance is safe.

You can buy BA miles directly, have a look when you login to BA.com, it should be an option in the left hand menu in the exec club section.

However its not a very cost effective way to get them, - but it is simple and easy.

Alternatively, transfer a small amount of some other credit, say a hotel scheme, or a hotel stay etc, into BA miles - just to keep the balance safe.

As for spending the BA miles, that needs to be for travel. The most bang-for-buck is generally considered to come from using them to upgrade from World Traveller Plus (premium economy) to Club World, for which you might want 25k.

However it doesn't sound like you are contemplating travel right now, so I'd just try and get something to credit to the account to keep them all safe.

I'm assuming you are a North American member, I don't know which are the most cost effective earning partners in the US, however if I was in your position it would probably be cheapest for me to divert a hotel stay to BAEC.