looking at two local seats of Eastbourne and Lewes will show you how the voters float between Liberals and Tory. same applies to most the southern seats Liberals lost, they were Tory seats before the 90's. the sort of tactical voter who might swing to the Liberals isnt going anywhere near UKIP. another misreading is how far right the Tories have gone, with the backbenchers seeing off changes to working tax credit and ending austerity in all but name a year ago, there isnt much evidence for a lurch right, just a lack of an opposition as Labour fight amonsgt themselves.
OK, take that argument on board re: LDs / Tory swing voters. I suspect my error here is in placing too much emphasis on the LDs' history left-leaning social side of their history. I do still have some questions over the Ukip vote at the last GE, though - it surged in many regions, and I would not be surprised if that was protest-vote (and Brexit-favouring-vote) driven rather than being a true reflection of how many far-right voters there are out there.
The rightness I worry about with the Tories is only partially policy driven. It's also about how they've failed to appropriately deal with the rise of far-right parties, because their rhetoric (whether backed by policy or not) has (had) shifted to the right in an effort to stem the flow of voters (and MPs!) from Tory to Ukip. The Tories to me feel like they are actually in a very similar position to Labour at the moment, they've just handled it (publicly at least) better than Labour has. Just as Labour is currently facing a centre-left vs further-left crisis, the Tories have internal issues with centre-right vs further-right and those struggles are far from over just yet - the Brexit negotiations will continue to cause that pot to simmer.
Re: the end of Austerity in all but name - it's worth looking at the finer detail of what happened with tax credits. First, it is worth pointing out it wasn't the backbenchers who forced Osbourne the "abandon" the changes - it was the unelected Lords. Secondly, while Osbourne announced to great public fanfare that he was completely dropping them, the reality that actually happened is that he quietly kept a core of the changes in - he simply moved a few chairs around the room and pulled some wool over enough eyes to get away with it. And we of course are still under the burden of austerity policies that were already in place (such as the budget starvation of the NHS and drive to privatise it, the over-zealous clamp down on disability benefits to name a couple). For me, the Tories are still sitting further right than I would want them too.