There's reason to be wary about the Libs' handling of the Senate, as Thomas Walkom writes in his latest column. But it's also worth noting that contrary to Walkom's conflation of the two, there are important differences between selecting prospective Senators based on whether they "back the Liberal government", versus evaluating whether they are "amenable to passing bills the Liberal government wants enacted".
Indeed, if the Libs want to defuse any potential for controversy while avoiding Senate obstruction, the one key requirement should have nothing to do with support for their government in particular.
Instead, any new senators could be screened (among whatever other criteria the Libs want to apply) based on their willingness to generally support all legislation passed by the House of Commons regardless of its party of origin. That could be subject to variation in exceptional cases, such as where MPs who have actually contributed to passing the bill signal a need for a bill to receive further review or amendment - but the overarching principle should be that the Senate will not get in the way of the decisions of elected representatives of any partisan stripe.
If the Libs limit their appointments to new Senators fitting that description, that strategy would simultaneously avoid the Cons' cynical obstruction and set the groundwork for an institution designed to function on a non-partisan basis in the future. But if they listen to Walkom's concurrent message about looking for political supporters, then we're all too likely to end up with yet another set of faux reformers (much like Harper's nominees themselves) who end up serving as nothing more than partisan tools.