Newbie / Sprint Questions

Hey all. I completed a sprint back in 2018 in 1:02 and change. It was however really short (250m swim, 10mi bike) and the swim was in a pool. I'm mostly an (oft-injured) trail runner who has decided to do another tri because I'm doing enough cross training now it feels like it would be a waste not to. I've set myself a goal of finishing a sprint in May in under an hour. So I've got some questions:

1. If I continue to focus on running (I really want to break 5:00 in the mile) how much is that going to hinder my overall progress? My understanding is I really need to focus on the cycling to take larger chunks of time off. 2. Assuming I'm well trained, done a bunch of bricks and didn't slaughter myself during the bike how close should my 5k time be to such a time in a run only event? i.e. I'm in roughly 20:00 shape right now (and hope to be in better shape by then) is it crazy to think that I could do the 5k portion of the triathlon in 21:00 or would it be closer to 23? 3. I understand that my old road bike (Scott 303 from the mid-90s in ... questionable condition) is a limiting factor. However outside of a tuneup and slapping some aero-bars on it I don't really have the cash for much else. Are aero bars the primary change I should make? I have SPDs on there, would I be better off going to clips for the race to minimize T2 time? I had a friend fit it to me about 4 years back, that mostly involved shortening the stem. 4. Do you have any suggested sites for bike or swim specific workouts? My rough plan will have me doing 1 workout, 1 long day and 2 easy days for each / week (I'll include drills during swim days). 5. Is it best to stick to the "hard days hard, easy days easy" mantra even if that means a hard day might include a lighter workout in all 3 sports as well as a 20-30 minute lifting session? Or do you spread things out a bit more when training so many sports? 6. What are the most important swim drills you do? I'm planning to get a few open water sessions in when it warms up here to practice sighting. Most of my swimming so far is just easy, focusing on keeping my head down and legs up (i.e. don't swim uphill). 7. Wetsuits... are they practically required since they give you buoyancy? Can you suggest any places to find a used one? I have a shortie that my Dad used to use for water-skiing... are those significantly different than ones designed to let you swim? 8. Is my goal reasonable? Too conservative? 9. How in the world do you all get enough sleep ? Running 7 hours a week with a family makes things hard, I'm contemplating adding more swimming and running and trying to figure out what I can cut out of my life.