Wow, 18 views no comments!
I'm not qualified like some of the others, but I can take a stab at it.
If you've only been at it a few weeks, as you said, you probably want to prioritize these three races. Pick one to emphasize. If those road races appeal more to you, I wouldn't flat out hammer it on the time trial. You've only got one and a half days to recover, and then you have two races in one day. A highly trained athlete could hammer it out on all 3, I think you'll have to do some budgeting.
Most guys in a TT will be running a HR monitor and / or a power meter. They'll know almost exactly what HR they want to hit, or what wattage. If you're not running either, you're simply going to have to go by feel, or RPE. Do you know what it feels like as you edge closer to your anaerobic threshold? The lactic feeling, the ragged breathing?
My advice would be to get your position dialed-in first. You want to be comfy so you can hammer the entire time. Second, take the 6th off. The day before, the 7th, do one 12 minute piece at your maximum percieved pace. Rest perhaps 5 minutes, then do 3 intervals of 2 minutes each at above-threshold. On the day of, get there early! Do a few 3 to 4 minute intervals at race-pace, and sprint out the last few seconds. Get to the line sweating.
In a TT, there is no riding defensively, nor much strategy to speak of. Most advice I've seen recommends "riding yourself into" the race; do not overdo it in the first 5 minutes! You'll blow up and go into serious oxygen debt and will take some time to recover. I heard a metaphor once of a carpet unrolling: it takes a while to roll out, but as it does, it picks up speed, until it slaps out at the end. Try to ride faster right at the end. You shouldn't be able to sprint, but you will hopefully be increasing speed as you go.
I can't really tell from your post what exact speed you should be trying to achieve. Speed, anyway, is a trap, as it depends on conditions such as the bumpiness of the road, the wind, hills, etc. If you're not running a HR monitor or Power Meter, you'll simply need to rely on feel. However, having said that, if you're 'comfy' at 31 km/h, then I imagine over 30 odd km, that you should be able to hold between 35 and 40 km/h. It's really hard to tell though without some other data, such as your avg. race speeds in some other events.
All the best!
