Hey how's it going, I'm buying a Mk6 Fiesta in a few days and looking some advice about it

It's advertised as a 1.4TD ZETEC CLIMATE 5door
It's year 2007 with 75k miles
I don't know the engine code or anything specific like that

I'm new to the ford game so I have a few questions..

1) what's the difference between TD and TDCI?

2) what does Zetec and Climate mean?

3) just by doing a small bit of research on the 1.4td, a lot of people seem to have needed the injector seals replaced, is this a common problem and is it expensive? How often in terms of mileage do they need replaced?

4) are there any other common faults/things to look out for with these engines or cars in general?

5) I noticed when I went to start it the glow plug indicator light didn't come on even though it was quite cold (icy) outside so does anyone know the minimum ambient temperature before the glow plug indicator light comes on?

6) I'm used to v/ag tdi's and noticed that the fiesta didn't rev quite as quickly from idle in neutral as the vw tdi engines did. Is this to be expected? It might be because it was cold

Sorry for all the questions I just wanna learn :P anyway thanks in advance for reading any help appreciated