domain mapping and bumping up seo in wordpress.com vs. wp.org

Hi, I previously had a site on wordpress.com for 5 years (with close to or over 1000 posts). After a couple of years, I used domain mapping to a url.

When I switched over entirely to www.remarpro.com and changed to a new theme at the same time – I did it gradually in order to preserve my google ranking – my posts stopped appearing in google alerts on my blog topic (they always had previously).

It seems that I still had domain mapping even tho I was not paying for it any longer – and this somehow interfered with the alerts. At some point, after awhile, the domain mapping went off and my posts started appearing again in google alerts.

However, now they have stopped again. The wordpress.com site still exists on its own with a link to the www.remarpro.com site.

When I posted there at the wp.com site recently with the link to the *new* site (it is now two years old), that post showed up in a google alert – so it seems the wordpress.com site has all the seo juice, so to speak.

I am wondering whether I should put domain mapping back on to the wordpress.com site and perhaps that will help with my google rank and appearance in google alerts.

Any thoughts on this?

Thank you.