Thank you for this interesting question. I’ve added my comments at the end of each paragraph.
'Pay rent and all bills on time. There are various aspects to household bills. To begin, the bill arrives. No-one wants to look at it, of course - especially the electricity bill at the end of a long cold winter when you’ve spent a lot of time at home pretending to study. So it needs to be put somewhere where it won’t just disappear - have a box or a clipboard or some spot for all money things that isn’t going to turn into a rubbish pile or get buried under old newspapers. A good system is a household concertina file with sections for the various bills, receipts, letters to the agent etc.
Comment: I think the topic of this paragraph is patronising because most people have an idea of how bills should be dealt with. However, I don’t think the language is patronising. In fact I think there are some advanced structures in this paragraph; e.g. “especially the electricity bill at the end of a long cold winter when you’ve spent a lot of time at home pretending to study”. There is also some advanced (or high-intermediate) level language; e.g. clipboard and concertina file.
Then a responsible, brave person - preferably appointed to this job - must check the current bill and claim the appropriate contributions, no doubt in a mess of cash and pieces of allegedly convertible paper. This can involve much chasing of flatmates and is a fairly thankless business.
Comment: The phrase ‘a responsible, brave person’ could be considered patronising by a native speaker. You could change that phrase for something like “then somebody must check the current bill”. However, I’m not sure a student would find that phrase patronising; very often what a teacher considers patronising makes students smile. The end of the paragraph from “no doubt in a mess” to the end is also patronising in terms of the advice but is actually complex language. It really depends on your aim with this text; if you want to expose your students to advanced level language, you should keep it. If you want to expose them to adult ideas, then I suggest you change it.
Then as the due date approaches, the bill must be paid. With most bills there are various ways. A good way is to have it all in cash and pay across the counter at the post office. This gives you a receipt, which is most important and always should be kept - you never know when you are going to need to prove what you have paid, or to unravel contributions. The really efficient household will also give receipts to
one another as contributions are put in'. (Taken from Norris, Ortenburg & Norris, 2000, p. 49)'.
Do you have any suggestions regarding how it could be re-worded or not?
General comment: I don’t think the language is patronising but I do think the topic and how it is described is very patronising to an adult. In order to make it less patronising, I would turn all comments into imperatives as follows:
File the bill
Check the bill and the amount on it
Calculate each person’s contribution
Ask flatmates for their contributions
Pay the bill and get a receipt
File the receipt in a safe place
I will emphasise my point here that by making the topic less patronising, the language is much simpler.