Need help training/improving bike times

steady as possible will net you the best overall time.  You don't want spikes in power that cause unnecessary muscle fatigue.

During training, it depends on what you're focusing on for that day what you do on climbs, descents, etc.

My strategy is to go as hard as possible on the bike, then blow up spectacularly on the run.  YMMV.

It depends upon length of race and length/steepness of hill.  In general, ride up hills slightly harder than the flats.  Do not ease up at top of hill.  Keep effort same as on hill until you are over the hill and have re-established speed.  On a short riser, might go a bit harder for a very short time to maintain as much momentum through the hill as possible.  Keep pedalling downhill as long as you have enough gears to do so and it's still worth the effort (again, it depends somewhat--e.g., in an HIM I might start coasting somewhere ~32-35mph).  On flats, steady pacing for the most part.  Might later slightly to take advantage of 'legal' draft opportunities but, unless you are riding around someone at a very similar level as you, this is often more trouble than it is worth.

In general, you want to ride the race as steady as possible with the exception that it is 'worth' it to go a bit harder than your steady pace up hills and into the wind (assuming there are downhills and downwind on the course--reasonably safe bet in most tris, which are loops of some sort)

+1