Yeah, I did the same - a couple of seasons with clip-ons on my road bike before buying a second hand TT bike, and then a few years later building up a new bike from scratch with lots of fancy parts. The limitations of clip-ons you've described are definitely there (although I tend to ride quite an aggressive, low position on my road bike which helped that part at least), but my gains for each change have got increasingly smaller and increasingly more expensive! A pair of <£50 clip-ons, a decent helmet and skinsuit gave me my single biggest time advantage (although my current TT rig is still definitely the quickest and 'sexiest' of the 3 set ups I've raced with). Spec says its 5800, so 11 speed at least, and a decent gearset.
Plus they can fix it! Magic really. But I might go old school and back to steel for my next bike. My custom titanium 29er is fabulous but I'm really not sure for a posh, 20 miles a day commuter, it's worth it...
The older style titanium frames with straight gauge tubes had a reputation for being indestructible but modern titanium frames with milled/butted tubes are no stronger than aluminium frames and in some cases worse. I do love titanium though makes a beautiful bike frame.
All jokes aside, weight doesn't matter so much when most TT courses are as flat as they can find. You need to start messing with the setup though to switch it into "TT mode". Stem lower, saddle may go up slightly and usually forward. Gears out of reach etc, depends on your course incline how much you need to use them. Rake on the fork is different too. The saddle itself will be a different style. I used to do this for years and its a pain. I agree with looking for a second hand one though. It's missing the 105 brakes (Tektro) *and* 105 crank (FSA). Also being 2016 will be an older revision, 5700 I think.
At least he’s enjoying himself (lol)