How to quickly join the development on MODX with experience with other CMS?

Question

MODX

The situation is as follows:
I have experience with Drupal, Bitrix, Wordpress. PHP, Mysql, Html, CSS don't bother either. I inherited a site on MODX, which I had never dealt with before. Using the method of scientific poke, googling and picking in the database, I figured out something, but it seems that I still do not fully understand it.
Questions:
1) When transferring a site between hostings and when changing domains, you need to change the config in 4 places, indicating the path to the folders from the root. Isn't it easier to write, for example, $_SERVER["DOCUMENT_ROOT"]."/core/" and drive the site back and forth? Or is there some trick here?
2) Templates are stored in the database, after other CMS it is terribly inconvenient, is it possible to somehow import them into files and edit them so that it is more familiar to work?
3) It is not always clear which template belongs to which page. If it’s more or less clear with the main templates, the template is specified in the page setup, but the site also has a version for the visually impaired, on which other templates are applied to the same pages and it’s possible to match them with the page only by scientific poke. How would you understand how the template is related to the page?
4) The site starts to slow down from time to time, what is the best way to find the source of the problem? At the moment, the site has about 1500 pages.
5) There is a uni_sessions table, my predecessor did not clean it, it has grown to 1.6 GB (!). I cleared it and everything works fine. Is this how it should be done, just clean it periodically, or is it a syndrome that MODX is crooked?

Answer 1

The site starts to slow down at times, what is the best way to find the source of the problem? At the moment, the site has about 1500 pages.

https://modstore.pro/packages/utilities/debugparser

Answer 2

1. I can’t answer, because I abandoned my modified version of MODx a long time ago, maybe I tried to change the paths. Try to change it)
2. Yes, this is the main horror of MODx, so I usually store in the database only the connection of files where the templates themselves are located
3. This is a problem of any template engine (hell understand where the legs grow from)
4. Clean the cache periodically, otherwise, when it it will get clogged, the site will fall
5. You will also have to periodically clean it, the system most likely registers all visits to the site in a row, I won’t be surprised if you found a lot of bots and crawlers there.

Answer 3

1) Yes, you can set the path variable in config.core.php, but it's easier to roll the update when transferring.
2) https://zooks.ru/web/979
4) There is a special plugin for searching for slow queries.
5) Yes, that's right. There was information online on how to fix it.
In general, I recommend not to get into MODX, and even more so not to start new projects on it. Only if there is no other choice.