Drivetrain refresh Carrera Virtuoso

Hello all,

I need a sanity check before I commit to this.
I’ve got a 2020 Carrera Virtuoso from Halfords that’s been absolutely rinsed over the years. Hanger’s bent back, had a few run-ins with kerbs and the odd car door, but she’s always been kept inside so no rust. Frame’s heavy but solid, wheels are fine, and I want the environmental guilt of chucking a perfectly good frame just because the drivetrain’s knackered.

So I’m planning a full refresh and getting a local shop (I’m in London) to fit it all for £70 as part of their full service. Here’s what I’m buying:

• Shimano Claris RD-R2000 8 Speed Rear Derailleur (GS – Medium Cage)  
• Shimano Claris FD-R2000 Front Derailleur (28.6/31.8/34.9mm)  
• Halfords Replacement Gear Hanger C  
• Shimano Tourney FC-A070 7/8 Speed Chainset (50/34T, 170mm)  
• Shimano CS-HG50 8 Speed Cassette (11-28T)  
• Clarks 6/7/8 Speed Chain  
• Clarks Universal Inner Gear Cable  
• Clarks Universal Inner Brake Cable  

Planning to reuse the outer cable housing since it’s still alright. Brake pads and tyres are fine too.

Here is the bike

https://www.halfords.com/bikes/road-bikes/carrera-virtuoso-mens-road-bike-2020—white—s-m-l-frames-348270.html

My questions:
1. Does this all work together? Anything glaringly wrong or incompatible that I’ve missed?
2. Chainset – I know the Tourney is technically a downgrade from Claris, but I couldn’t find another 50/34T square taper crankset at Halfords. Is this going to be a problem or is it fine for what I need? Open to suggestions if there’s something better that’s not stupidly expensive. (It’s a Halfords bike so I’d rather stick with stuff I can actually get from them without dealing with Amazon faff.)
3. Worth doing it myself? I’d love to learn but I’ve got literally no tools and no workstand. Is £70 for a full service + fitting all this lot reasonable for London, or should I just bite the bullet, buy the tools, and YouTube my way through it?
Backstory: I’m fed up cycling on a dodgy bike, she deserves some proper TLC, and I want to use her for triathlon training (not my actual race bike). Really don’t want to buy new, I just want to keep this one going.

Thanks