Hello David,
Where are you located in PA? You're welcome to try my recumbents if you're local to me.
1. What are the advantages or disadvantages of having two 26" wheels versus a front 20" wheel and a rear 26" wheel?
Pro: Same size front and rear wheel means less spare tube to carry.
Larger wheel sizes roll over obstacles easier, less rolling resistance.
Con: Sit higher off the ground and higher bottom bracket feel less stable for beginner recumbent rider.
2. It seems that most bents have nine speeds, while my current bike has 24 speeds. Is nine speeds truly sufficient for a bent? Or is this something that might be improved--if necessary--in the future?
The number of gears doesn't necessary reflect the gear range of the gearing, but the more gears you have on the rear wheel the tighter the gear ratio between the cogs. Range of the gearing is determined by the number of teeth on the chainrings and cogs, not the number of gears available.
3. I would like to purchase a bent that can tour so it must accommodate racks, but it also must be relatively fast and have higher end components (without getting too carried away). Is that type of bent available for around $1700 or less? If so, which one would you recommend? I might spend more, but really don't want to.
Touring recumbent may not be fast, fast recumbent may not do so well with loaded touring.
You want high performance, you pay the high $$.. no one wants to spend more money then they have to, but the mindset of getting everything at the lowest cost will cost you eventually, whether it be your annual income, health insurance, or even your job going overseas.
4. The bent rider's feet and legs sit "high" above the ground on the pedals. Could this high feet/leg position contribute to a fall-over because the rider could not plant his or her feet on the ground quickly enough in an emergency situation?
It's all about getting used to the bike that you ride. You may fall, you may not fall, how quick of relax do you have? practice getting on and off the bike so that you have quick reflex to react to emergency situations is what you need.
5. If you own a bent, what do you especially love about the bike? And what do you dislike about it?
I own/ride a Vision R40, I could keep up with local group rides in Valley Forge area averaging 14-15 mph amongst the hilly terrains. Your result may vary.
I've been riding/racing Diamond Frame bicycles since 1994, I've logged over 2200 miles in this year so far.