@lukestokes - It is great that you are going to attend Steemfest. I think experienced Steemians like you who have worked their way through Steemit over many months, who are very familiar with Steem stats and also with witness duties will add a lot of value to the discussion. Relative newcomers like me will not really add much value. Of course, it would help newcomers to go there for networking but I do not think I will be going this year. Perhaps next time when I have gained sufficient understanding.
If you have never been to Europe, I think you will find the experience quite charming. I always find European cities and architecture to be a bit more cozy, personal and quaint compared to US. The lifestyle also is a bit more unhurried and conducive to musing, romance and admiring the historic perspective , in most of European cities.
Lisbon is quite charming with it's blend of historic and new buildings. It is an interesting city with hilly areas and beaches in proximity. I am sure you will enjoy your stay (apart from attending the exciting Steemfest)

I see that @dvhaley has already answered most of your travel related questions. So I will not repeat.

About your question on what I would like to ask at Steemfest - I think my major question would be 'What do the founders think about how Steemit has evolved'. I would love to hear the vision behind Steemit in their own words and also get their perspective on whether Steemit is doing well in terms of evolving towards attaining that vision.

Hope to see you in next Steemfest. I wish you a very fruitful, engaging, exciting, comfortable and safe trip. Will look forward to the blogs about the trip.

Regards,