How to properly redirect a site?

Question

Google

Good afternoon.
There is a regular corporate website that offers certain services and portfolios, divided into categories.
Services:
site.ru/services/
site.ru/services/design/
site.ru/services/develop/
Works:
site.ru/works/
site.ru/works/design/
site.ru/works/develop/
Menu site on the main page, we see links to the Work pages - site.ru/works/ and Services - site.ru/services/, these pages now contain only links to categories.
It seems that everything is logical in structure, but it turns out not convenient. Since in order to see specific works, he needs to make an extra click to open the category and already go to the view.
At the same time, the customer does not want to display the latest works or services on this page, as he believes that this will be a page with garbage and the user will start watching it and may skip links to categories, which will result in a negative user experience.
Following the example of an online store, it will not be convenient to immediately see, for example, tablets, microwave ovens and the like in one list, this will not be of any use.
It also makes no sense to make selections on this page (as in IM) with useful, best, latest services / works.
We also proposed to make a drop-down list of categories on the main page in the menu, by which the user can immediately select the desired category - which the customer also refused.
In fact, the site.ru/works/ and site.ru/services/ pages were not needed on the site, more precisely, they were needed only for the correct site structure and for SEO.
The customer of the site suggests that when you click on "Services", the first category opens immediately.
That is, when you go to site.ru/services/, to open - site.ru/services/design/.
There is a convenience in this, because if the user is already interested in this category, he will simply stay here. And if another is needed, it will make an extra click, which in any case it would have done on the current implementation (when, when switching to services, it sees only links to categories).
Personally, I support this option, because when you really go to the page, you immediately intuitively understand that the first category is open and if you don’t need it, click and see another.
Actually there are questions.
1) How correct is it for SEO and in general to redirect via htaccess from site.ru/services/ to site.ru/services/design/ ? If so, is it better temporary or permanent?
2) Or just make links to the first categories in the menu, and let the site have half-empty pages with categories for the structure? site.ru/works/ and site.ru/services/
3) Maybe we did something wrong in general and there are better solutions?
Thanks in advance for your reply.

Answer 1

1) stupid, do it right away site.ru/design
2) pages need to be filled

Answer 2

redirect HTTP 308 Permanent Redirect (and HTTP 301 Moved Permanently) so that headers are not cached and fix robots.txt so that it does not go to old sections, see MDN 308 MDN 301
I personally use NGINX for this kind of tasks, and do not touch htaccess, let him live, since NGINX has everything you need for a redirect and fine-tuning without any changes on the server side, in principle, even developers do not have to be notified about changes, with the right approach to business, and all your headache will be reduced to an elementary configuration file, provided that NGINX can itself validate its own configuration file, this is priceless. and all paths on the server are considered unchanged. and don't suffer