New Tires

Yesterday I stopped by the bike shop. Several things on my mind. The Fuel EX7 needs new tires, the hardtail is soon needing tires, looking way to ride faster on one bike, and considering a road bike.
I was armed with information and questions from my cycling books and bicycling.com.
Should I look at purchasing a cross bike, a road bike, or modify an existing bike? Which bike and what components? What is a "plush" road bike? That and look a new tires.
Regarding a "plush" road bike - that is a less aggressive, more upright bike, like the TREK Pilot (see photo).
To get some more speed on my pavement rides, the hybrid is getting 28c road tires. Thought about 25c tires, but I want to be able to ride on the Trace once in awhile with that bike. Zack and Blaine agree the 28c tires is the ticket.
Zack has a pair of tires that will fit my Fuel. They came off from a customer's new bike. Getting them at a friendly price.
When counting teeth on chainrings and cassettes, I noticed that the tires on the 4300 are really getting in bad shape. Very concerned about riding it until it gets new tires. Was hoping to stall that purchase until next year (as it will get the studded tires this winter).
So, today starts testing for modifications and perhaps a new bike. And for my dirt riding friends, I am not turning to a "roadie", just looking for more variety.