(1)Rising costs will have a negative effect on international trade, ENDING IN a return to "localised production".
I agree that 'resulting' might be better, but I don't think 'ending' is wrong grammatically. The question is only whether it fits logically, whether the writer really sees it as a final, irreversible step -- the end of an era of globalization, say.
(2)The novel deals with a wide variety of topics, e. g. social problems. To begin with the class system in this town, I want to exemplify it with an example.
Tsk tsk tsk. The first sentence would be better with 'such as,' instead of 'e.g.' without its comma. The second sentence needs major surgery. I would just start over. 'For example, the rigid class system in the town of ________ is the source of much hidden conflict.' If you must leave some shreds of it remaining, maybe 'To begin with, I would like to consider the example of the class system in the town of _________.' But really, 'To begin with' is a little too casual -- 'First' or maybe 'To take one example, the class system is ...' would be better. And 'I would like to' is stylistically out of place in an academic essay. You don't have to ask anyone's permission to make a point; the reader is already waiting with bated breath for your argument. So when you think of something to say, just say it!
(3) She also fights for social equality, EVEN IF NOT AS DIRECTLY AS character XY does.
Fine; or 'perfectly all right / okay.' (I wouldn't use 'quite' there; it's better with 'not,' as in 'not quite right.')