first stage race

Based on your july numbers, you should be a shoe in for the tt. 5.5watt per kilo ftp is enough for a pro contract. Go you.

However, for the rest of the race, you're going to need to build the actual skills to utilise that engine.
Group rides, lots of group rides, and if you have one, get on the mtb and build your handling competence and confidence.
When it comes to nutrition and recovery, you'll be fine, day one is pretty light on total load. My tip would be to avoid the simple sugars, gels and energy drink before and after the tt... keep the rocket fuel for the crit and sunday.

Oh and sunday, if the legs are screwed, go with it, they'll probably come good by the end, and always remember that everyone has done the same as you, so theyll be feeling just as bad. I remember once spending a whole day in the break, like all day, and finishing in a total box. Next day, I was literally cramping on the start line... shredded, gassed, cooked. 3 hours later I won the stage... got to love stage racing.

What's the actual race @mak parshall? Name of it, area and also when is it? If it's March, that'll make a difference to your training and prep than if it's in September...

Whereabouts are you based? That makes a big difference in terms of the options open to you. If you're in London / SE then you've probably got a load of winter crits available to you, if you're in Yorkshire or Scotland then you won't have that!

And what level of race is it? Regional B or Regional A? You mention that you're a 4th Cat so those are the only two options open to you at the moment unless you're planning on getting your 3rd Cat very soon and then going for a National B? I'd factor in that, as a 4th cat, you may well not even get into a Regional A race so setting your goals at a stage win seems quite a lofty ambition...

Ultimately, the only way to get good at racing is to race. You will learn more in a season of crit racing than in 2 years of turbo training. or roller riding. Rollers doesn't do a huge amount for bike handling either. If you want to learn bike handling you need to be riding a real bike on a real road in real weather (CX racing is also excellent for teaching handling skills). Same with group riding - get out with the local club and practice holding wheels or go along to indoor velodrome training sessions if that's an option for you - great way of learning group riding while also maintaining / gaining fitness in a nice controlled environment.

Stage races are great fun. Did one in France earlier this year and it completely changes the nature of what we're used to from a single-day road race.

Sounds like you'll get through stages 1 and 2 easily. Trick is getting the recovery right for stage 3 on Sunday. A 40-min crit isn't that demanding carb-wise so just get a decent evening meal, maybe a recovery shake after the race. SIS stuff works for me. Beta Fuel and their Recovery shake.

Stage 3 sounds like an attrition stage. You might struggle to be competitive at the finish if you're getting dropped on the descents and wasting energy getting back on.

Maybe make stage 2 your primary aim? Means you don't have to go deep on stage 1 or worry about holding back for stage 3. Whatever you do, be specific about which stage you want to aim for. Many other riders will be holding back to do well on GC. Use that to your advantage.

Your current FTP is way below what will be required to be competitive.

If you were 345W for one hour earlier in the year, then with a lot of work you will regain it. Depending on how much time there is before the event.

Your bike handling skills will severely restrict your ambitions. Learn to handle a bike well. Get with riders who can teach you basics of descending quickly. Don't just go fast on an unknown road- that could lead to death

I dont know if your remember Bradley Wiggins, he was known to be poor a descending especially im the wet and he lost loads of time in the Giro. There are a few notable others who are crap at going downhill- Thibaut Pinot is another.

By the sound of it you need to concentrate on riding in a group, I would suggest that you get lots of group rides in until you can comfortably sit six inches behind the wheel in front and close enough that touching handlebars with riders either side of you doesnt bother you.  You also need to improve your descending and being comfortable at speed, all these basic skills (or lack of) will be a real problem for you in the crit and lumpy road stages.

Basically, get loads of group rides in over the next 6 months, relax, forget about power numbers but learn to be comfortable in a big bunch and good luck.

Where is this 6.5 mph TT? I could be in with a chance there (if I up the training) as I can hit 5 mph easy as long as it's a bit downhill with a following wind.

Nail on the head. Welsh boy.

Have you raced before or will this be your first?  iI your first then you may be in for a bit of a shock!

Well done for setting your goal as high as a stage win but in view of the fact that you are asking for basic infromation I think you may need to reasses that aim.

It is impossible to give you advice without knowing your level of fitness, course details, what racing experience you already have etc.  I dont know what you mean by a Mercky style timetrial either.

If you can come up with more info you may get some useful help but good luck with the race, stage races are great but can also be quite a shock to the system when you find that there is a specialist in each of the disciplines and the overall winner doesn't feature in any of the stage victories.