It seems you have no problem with refurbished laptops! Let's go through the list:
1. The Lenovo Yoga 510 has the best CPU and offers the faster AC WiFi standard. Good screen, but the graphics unit is designed for typical business tasks only, so gaming is limited to League of Legends-type and 2D hidden-objects games.
2. The Dell Latitude is decent enough - on par with the Yoga above - but makes no mention of WiFi, so I'm guessing it's the slower N standard.
3. The HP Elitebook mostly has an attractive price tag - not outstanding specs (less storage and an older i5 generation).
4. The ThinkPad T450 has great specs but only gives you a 900p screen, which is a bit odd and maybe not really a problem. At 1.3kg it's one of the lightest laptops on the list. Also the most expensive one.
5. The ThinkPad X1 Carbon 2nd Gen is a bit of "seek and ye shall find" - at £370 I'd say get this machine now before it's gone! Not the best in terms of specs, but you do get a 3K screen, and it's a fantastically attractive and stylish device that is rarely available on the refurb market.
6. The ThinkPad T440s is a £230 bargain - you only have to install Windows 8 yourself. If you know your way around computers and operating systems, putting Windows 10 on it shouldn't be a problem.
7. The HP ProBook is gone.
8. The Lenovo Yoga 3 has a German keyboard and uses a hybrid harddisk (mechanical with a small SSD partition).
9. The ASUS has a low price tag, the oldest CPU and not much storage.
I'm still hot for the X1 Carbon, with the ThinkPad T440s a close second.
Best of luck,