Multisite or separate installs?

Hello all ??

I’ve a multisite vs separate wp installs (on subdomains) decision to make, maybe someone can give some hints according to information below.

I’ve read multiple opinions and comparisions, so I’m not completely blank, but I couldn’t find a good answer to this situation:

I want my domain.eu to be multilingual, but my subdomain.domain.eu to be only in English.

My subdomain will show just a part of what I do (my new hobby – wordpress and other webrelated stuff), my main domain will serve as a general business card or a starting point to people who search for me (mostly or only static). Subdomains main content will be my web related blog.

Also about SEO – I’d like to work (more likely test and fail ?? ) with my subdomains (blog) SEO and promote it separately from main domain (for main domain it is enough if people find me when searhing my name).

I would like my planned subdomain and domain feel like separate websites (only connection in the frontend would be max one link).

I’ve been thinking that in my case probably a new domain (maybe additional server), instead of subdomain/directory, would be a good idea (since my daily work and other activities differ a lot from webprogramming/WP things), but since I will not have a lot of info neither in my planned main page nor in my planned subdomain, its hard to find good reasons to pay more money :).

So can anyone push me to the right direction please? ??

(If there is answer available and I was too stupid or lazy to find it, I’m sorry, please send me there and I promise I will try harder in future).