Uncanny similarities to my situation mate!
Snap on the first couple of lines about the YLOD (you wish you backed it up properly but more on that later), although for me this was back in November and I bought a super slim instead of going straight for a PS4. Used it for about four months as normal, then worked out that I had a whole load of decent games but only time to play a couple (as we have an 18 month year old) - football and an adventure of some sort. So I may as well trade everything in for a PS4 and play the same couple of games of a faster, flashier system!
The most striking difference so far between the experience on this and a PS3, to me, is the constant use of network. Better downloading/updating of software. I also learnt from the YLOD on my PS3 and have everything to backup to the PSN cloud automatically. All a lot smoother, you seem to be able to pause a game, drop into the XMB then back to your game with little need to quit. The PS3 may have similar network capabilities but it seems to be more of a focus on the PS4.
Playstation Plus is a must on the PS3 and you get some stunning deals on some of the free games, but on the PS4 this has yet to prove its worth with no triple A releases given away yet. However, within the year this will be a big plus.
Regarding games, FIFA 14 is the only option for footie. I've be Pro Evo since 1998, had dabbled with various FIFAs but never impressed. So I said "right EA, you've got six months to convince me". And.... I love it! Gameplay is excellent, ultimate team ridiculously addictive. You can get all this on PS3 so it looks to me that the biggest differences are graphical; animations, maybe detail.... and the crowd. Wow. Every person looks independent (not quite unique, there are definite clones). And though the scale is still not correct - I know the East Stand at WHL goes back about 28 rows to the back of The Shelf, but on FIFA its only about 15 rows - it looks and feels much more alive.
Never played Dynasty Warriors, and one of the biggest drawbacks on the PS4 is lack of games at the moment, with few of the ones coming through being jaw-droppingly next-gen. There is very little I have seen that couldn't be done on a PS3, save for aesthetics. Skyrim (online only) is due out soon, so I'm looking forward to that. The Playstation has always been a more mature gamers machine (as opposed to the XBox or Wii) and so there will be significantly fewer kids games, and as I've mentioned there is just a trickle of games in general at the moment.
On a few other points:
* By "good quality projector" I assume HDMI. If not, be aware that the PS4 has HDMI output only.
* iPlayer/ITV player etc all fine. If you have PlayTV though this isn't compatible
* Streaming games (I assume Spurs as opposed to Call of Duty!) (a) if you did this via an app like NowTV then check it is out on the PS4 (b) if you are managing to do this another way please PM me how!!!!
I love my PS4 but I am a long time games nut. I don't get a chance to play much, but when I do its fabulous and I am definitely enjoying my gaming more.
Finally, going back to the start I'm not sure what you were planning to do with your old PS3 stuff but as I said, I worked out I had a fair amount of value in games etc. So I did my research and found that CEX offered good trade in prices but their games are fairly expensive plus you can only buy second hand consoles from them. GAME have lower trade in prices but will price match CEX and beat by a pound. So games that they would normally offer about £2 for were getting me back £5 or so. Controllers especially you can get a good £20 for (maybe a little less now). I also sold my YLOD as faulty on eBay also with a fairly new 500gb drive and got £35 for it. So a bit of Redknapp wheeler dealering can pay dividends!
