In the current state of physics, is it fair to say that we have a situation of "we have all or many of the clues on the table, and we need to piece it together correctly" or instead the situation of "we lack sufficient evidence to make progress"?  My own view is that at any given time we are, and have always been, in the former situation, because it is that which informs experiments and a sense of 'what to look' in the first place. 

And 'we lack sufficient evidence' is often an excuse when issues lie with our methods of inquiry. A guy in the 12th century could have said we lacked sufficient evidence to understand why planets moved, but the problem was not a lack of evidence itself, but the methods he pursued: he probably had all the tools he needed to make a telescope or to do experiments, but he never did what he should have done with those raw materials to get the answers.

It’s common to hear "But quantum gravity effects are expected near Planck energies, Planck curvatures, tiny length scales far beyond current experimental reach."— and I think these are excuses too. Einsteins special relativity is an example. Special relativity is an effect that becomes noticeable at speeds closer to the speed of light, and yet Einstein did not sit around saying "we lack the technology to go that fast",—he figured out what would happen in those regimes with what he already had. 

A more epistemically disciplined method would take on what we already have and find out what it suggests will happen in regimes we cannot access. It is only when speculations run amok (by imagining whacky though experiments, for example), we say 'data does not force a unique solution yet.'

If we resurrent newton today and make him make sense of all the evidence we have so far, I think he'll likely come up with the most disciplined conclusions that almost certainly follow from what we known and for the rest, he'll stop and say 'hypothesis non fingo' and walk away. 

Here's the thing. Not all speculations are equal. Newton's universal gravity was indeed a speculation, but it is not the sense of 'let's guess something consistent and see if it works' (that's a more Popperian idea), but rather a sense of 'what are the generalities that hold for all instances we have looked at'. 

I think a Newtonian style requires equal measure of discipline and humility and restraint—discipline to piece together existing evidence and humility and restraint to stop where evidence stops. In contrast popperian style is one of excess—guess whatever you want, but make sure it is consistent, and can be falsified.

One may say, “But we need to make a bold hypothesis!” I think that’s also a Popperian stance, but Popper’s stance is based on an outsider's view. He was not a scientist himself, so many of the unobservable things look like bold guesses to him. 

But to the scientists themselves, the concepts they invent are often inevitably forced by the evidence. This was even true of Faraday's fields. I think Popper's main contribution is not in guiding scientists to do science, but in demarcating non-scientists ' supposed science from science. 

Curious but disciplined scientists already know how to do science.