You don't have to have exact same political core beliefs for cooperation.
We also have the most liberal president in pretty much entire Russian history; really, if anyone will replace him he'd have to be decidedly a lot less liberal to be popular. Only Putin's huge personal rating holds his liberal policies.
It is as liberal as it gets now; it will not get any better in next 10-20 years.
Nothing wrong with tensions here and there as long as you're ready to talk and reach compromise.Also, proximity is more often than not a factor for tension and disagreement...
Really, just imagine that - EU being "net resource exporter" just as long as it includes Russia... Ultimate "diversification" - your resources being protected by being part of your own system
It's a lot of work, sure, but isn't it good goal?