What MySQL storage engine and encoding should I use?

At Languages: Storage Encoding we have the default setup as per my screenshots attached.
My store in in English UK -

My questions are:

1 - In my case should I change Collation from utf8_swedish_ci / utf8mb4_swedish_ci to a different collation? If so, which one should be used for UK English? Bear in mind that I already have products added to my store and other settings set. Does this matter? What is the recommendation?

2 - The Engine is set to MyISAM. If is set to CSV, does this mean that all language related information will be stored as CSV, and if so where? Is it safe to change this now?

... my current langauge settings for English are:

Code 2 (ISO 639-2)
eng

System Locale
en_US.utf8,en_US.UTF-8,english

etc

For LiteCart 2.x the use of MyISAM was rolled out for maximum performance. (Or Aria if you used MariaDB).
swedish_ci is the default in earlier mysql versions but there are others now. English installations can use general_ci.

LiteCart 3.0 will default to InnoDB utf8mb4. Collation depends on languages installed.

CSV should not be used and will be filtered gone from the dropdown in an update.

utf8mb4 supports emoticons. utf8 does not. There might be a tiny performance gain with utf8.

In your case I would do crash-safe Aria or InnoDB with utf8_general_ci or utf8mb4_general_ci.