Your main big problem: you prefer do nor read docs and use tools blindly. Otherwise you have to know one of the biggest limitation of HgSubversion: it is not possible to push back to Subversion mergesets from Mercurial
"...Mercurial merges cannot be pushed to Subversion"
Also, HgSubversion page on Mercurial wiki clearly states:
The important point to note is that hgsubversion cannot push merge changesets to a svn repository. This means you should not try to merge this new head -- if you do so, hg push to svn will fail. Instead, you should rebase the changesets that you want to push to the Subversion repository (see Rebasing changes below)