Is a slight swelling of the battery on a MacBook Pro normal?

Question

macbook

I invited the wizard for preventive cleaning of Macbook Pro (late 2013) - recently it has become more warm.
*Despite the year of production, the laptop has been carefully used for only a few years.
He ran diagnostics from a flash drive (on Windows o_0), and began to tell me that all PPC is bad, the hard one has critical errors, 90 percent percent (although Fan Control shows 60). We opened the laptop, the coolers were dusty, and the battery was a little swollen, here is a photo and video:
The master refused to close the lid, said that everything would explode / catch fire at any moment, an urgent replacement was needed, etc.
Friends, tell me:
1. Such a slight swelling of the battery is generally dangerous or normal?
2. What to do with it, if you change it, please recommend a reliable and not very expensive service in Moscow.
3. Diagnostics of a macbook through Windows on a flash drive, is this a common practice? How to check it on your own?
Thank you in advance for your time and your answers, thank you)
PS Issue resolved for 6500r. (battery replacement, thermal paste and work) with the help of a specialist on Gorbushka (found through friends), a service that tried to "breed" apple-repair.ru
PPS In fairness, I will say that the service director apologized for the employee and offered a 20% discount, but the desire to bear I don't have my work car there.

Answer 1

Bloating a battery is very dangerous. If the packaging is slightly damaged, there is a non-illusory chance of fire. So the battery needs to be changed. True, there are at least two important "buts":
1) The battery on the MacBook Pro Retina is part of the topcase and officially changes only with it. So I don’t recommend changing from the officials, it’s expensive. You can order on Ali and change it yourself, it's easy. It can be significantly more expensive to replace with unofficial ones, but perhaps this will be the best option, because ...
2) Without a battery, a MacBook will turn into a typewriter. That is, it will work, but the performance is reduced by the system very much. It feels like the maximum processor gives out 15 percent, because even open "system monitoring" is able to load one core by 75-80 percent. This is done because the MacBook can consume more power at load peaks than it receives from the adapter and, accordingly, in normal situations, the battery compensates for this. And without a battery, the laptop is downgraded by MacOS to the level of a typewriter. Therefore, replace with unofficial ones for a double or triple price with Ali, but "here and now" may be the preferred option.

Answer 2

If there is swelling, then the battery must be changed / removed.
It is dangerous to use bloated.

Answer 3

Older Macs with a mechanical trackpad have a bug with battery swelling. She starts to press on the trackpad and it will stop being pressed. It is treated only by replacing the battery, so if you already have such a model, you can slowly look after a new battery.