we have a parent domain parent.com with multiple subdomains like sub1.parent.com, sub2.parent.com etc. we have been requested to move sub1.parent.com to a domain of its own i.e. sub1.com, due to marketing reasons(to monetize more).

the "sub1" site generates major chunk of traffic and has enabled our parent domain parent.com to have good ranks(subdomain passing its juice to parent domain) specially in Alexa. Currently parent.com is ranked 15 in Saudi Arabia(actual figures), which is one of our primary targeted market.

Solution 1
Now, if we migrate the subdomain and implement proper 301 redirect, what will be the impact on following(nevertheless, there may be impacts which we are not aware of)

1- Effect on rank/stats of parent domain i.e. parent.com after subdomain i.e. sub1.parent.com migration(currently the domain parent.com has Alexa rank of 15 in Saudi Arabia)

2- Once subdomain i.e. sub1.parent.com is migrated to its own domain(sub1.com), what will be the impact on its own rank, value, stats, indexing etc

3- What will be the impact on google analytics

4- What will be the impact on the parent domain parent.com google rank?

Solution 2
We were evaluating one alternate solution also, which is:

What if we run the site from two domain(subdomain sub1.parent.com and parent domain sub1.com)

a. Again what all impacts would be there(same questions as above)
b. How the SEO would work
c. Will canonical solve our problem?

Any alternate viable solution is welcomed.