Many landlords will not spend any money on property, period.

Contracting a local plumber might cause more costs and problems than it is worth.

The low cold water pressure may be the seasonal lowering of water pressure by water companies to preserve water.

This was supposed to have stopped a couple of years ago, but I had heard unsubstantiated claims that it had started again. It would not be worth you installing a pump, and pressure may go back up once rainy season starts in full.

As for you hot water, I guess that one tap is connected to a new solar heater, and the others are connected to an older system.

A quick fix would be to buy electric hot water heaters yourself, and take them with you when you leave. The simplest type is like a tap/faucet with a heater at the base that replaces your tap. They can be fitted in 5 minutes if you have a power socket in your bathroom, simple DIY job needing a screwdriver only. The one I bought on Taobao even had someone come and fit it free in the price (currently 169) detail.tmall.com/[...] OK you should not have to buy it your self, but reality is you will have to. You can get cheaper ones, but Haier is a good brand.
If you want to shower you can get similar instant water heaters or you can get the ones with a tank that you heat up before you take a shower. Apparently this type are not energy efficient and leaving them on all the time is expensive.

Again, buying on Taobao or Tmall you will get a better price and if you buy from a reputable brand you get aftersales service and in some cases installation services.

You may be able to negotiate with your landlord, if you do all the work (some are too busy or can't be bothered). If not you will have to pay, but you can take them with you or sell them, when you leave.

If you are thinking of home schooling for your children, it may be wise to sign up and enroll your children into a homeschooling program before you leave your own country.
Some home schooling programs have existing agents in China, and these are tied to specific education companies. These education companies are strictly controlled and the one I am familiar with you could only enroll children enrolled in, and attending, schools within their B2B customer base.

Another thing that can happen with agent rights is that someone gets exclusive rights to a licence and never gets their business off of the ground. As such the program is stuck in a kind of limbo.

If you enroll your kids before you leave home you can avoid these issues. You may also pay lower fees.
Just thinking aloud.

Yes I can see that, now. Unfortunately I would have to call in help to do that. We use the kind that has curtains that wrap around the bed and go down to the floor. No need to struggle with the mattress and easy to take down to clean.

A slight tangent, if you want a quick fix, there is a product sold almost everywhere in China named HuaLuShui. There are two fragrances and two types, one type is a very effective mosquito repellent that is alcohol based and non sticky and it lasts up to 12 hours. It comes in glass bottles, or pump spray bottles.

The mosquito repellent one has a mosquito with a bar going through it on the label. Not expensive.

No place better than Walmart, Carrefour, for price. The bedding shops charge silly money. Metro north might have them, Metro south is too small. Some local chinese chain supermarkets carry them this time of year.

If you have a choice, get the ones that do not have the full mesh at the bottom, otherwise you will lie on the mesh, unless you put another sheet down. There are also bamboo mats that you can put down, but it does not really get that hot here, and these mats can attract other insects.

The mosquito nets usually come in 3 different sizes, 1m, 1.5m, and 1.8m.