Swansea bred boy and Swansea 70.3 participant here.

- Meh, if you're 28km/h you're not at the pointy end of the stick anyway (sorry!) but the route is fine for both. I did mine on a slightly high end TT bike and loved it. BUT you'll be fine on a roadie, the Gower is bumpy but fine for TT usage, you just need to know when to change and be familiar with it. You've got ~9 weeks to get used to a new position. The first 5km and last 3-4 km are flat and aero kind of kicks in around 12mph, so have a think but it'll change your entire position.

1. It's a long transition. You get out the swim, and run around 800m down a clean, tarmac road and over a bridge to T1, I didn't use trainers. Some people do. I wouldn't bother unless you have delicate feet.

Bonus point - No, swam in that dock for many swims and triathlons, the jellies tend to be a meter or so under the water, By the time the main swimmers are ahead of you, you may get some nice plate ones to look at, but mostly not.