Hello Philip,
There is less ambiguity about the cars capability now.
As it stands you preferred choice of caravan Bailey 460/4 (MTPLM 1184kg) with the CX3 1270kg Kerbweight
Legally the caravan is within the cars towed weight limit.
This gives a conventional (MTPLM/Kerbweight) towing ratio of 1184/1270 = 93%. Conventional guidance would suggest this is on the high side for an inexperienced tow'er, but not impossible.
The conventional guidance also suggests that you should look for about 40bhp per Tonne power to enable the outfit to maintain reasonable speed
You quote 120ps = 118bhp divided by 2930kg (GTW) = 40.3bhp per Tonne
Thus on power the outfit would be just in. Most caravanners will tell you that "power isn't everything, and you should be looking at torque", which is more important as its the torque that gets the outfit moving, and you quote us 204NM at 2800rpm.
There is less easy to understand information about torque, but 204Nm is not unreasonable in my view, however it does come at 2800 rpm, which will mean you may find you are doing a lot of gear changes to keep the in the power band. In the past I have driven outfits with less power and torque, In fact most cars in the mid 1960's were petrol and had similar or poorer power and torque figures, so its far from impossible, its just that diesels with similar power and torque would be more relaxing.
Looking at the design of the car it has a relatively small rear overhang and this is actually good for stability when towing. it means that side winds on the caravan will have to push harder to start to move the car off line.
But despite the good points, it would still be operating above the advisory guidance, and very close to its legal limits. Its very easy to underestimate the collective weight of object you choose to take with you and being so close to the limits, it could be easy to inadvertent exceed them.
If you'd had loads of experience as a caravanner, then I'd be more inclined to say give it a try, but on balance I think its not really a good starting point.
Even experience of sailing where stowing items safely is important, you are generally not so concerned about the total weight of items (unless you are racing sailor) Loading a caravan is another important skill that needs to be learned.