SEO Big Questions [Canonical between 2 Domains]

I have a scenario with two of my domains,
1.mainwebsite.com - has lots of posts
2.website1.com - has only the homepage (basically only this website1.com)

What I'm about to do is this,
I want to set canonical only at homepage of mainwebsite.com to website1.com (I don't want to use redirect instead, for some other reason)

I have some questions regarding this,
1.Will the canonical link that (that I will set at mainwebsite.com (homepage) to website1.com) affect the link juice, will it pass the joice to website1.com, ranking website1.com instead of mainwebsite.com ?
2.Will this affect the posts at mainwebsite.com, will they disappear because of canonical that is set to website.1com (from homepage of mainwebsite.com to website1.com)? note: website1.com doesn't have any posts rather, only website1.com exists
3.If mainwebsite.com has penalty, will this pass the penalty to website1.com through canonical link that is set from mainwebsite.com to website1.com?

Note: only mainwebsite.com will be set as canonical toward website1.com and no other posts or page, for example mainwebsite.com/post1/, mainwebsite.com/post2/ the canonical there will stay default

Any answer will be appreciated