I won't harass you about the vagueness as I think that's pretty obvious (do you really want either federal judges or, god forbid, a jury of citizens to be the judge of what is "commercially viable"?).
The incentive to slow down comes from your 10-year rule: if I have a good idea that is economically useful, ceteris paribus the longer I wait to patent it the likelier I am to actually get an enforceable patent (b/c the prerequisites aren't getting any younger). Now obviously in some cases there will be concern that rivals or competitors will jump in front and patent it instead, but in many smallish fields there really aren't that many people working on the same topic at the same time and what competitors there are will all be operating under the same overall incentive (and thus will themselves have some incentive to delay as long as possible).
So the incentive to file for a patent immediately is the same as under the status quo -- make sure you get out ahead of competitors -- but you add in a countervailing incentive to delay that the present system (for all its faults) does not have.
This is particularly egregious wrt brand-new technologies (like, eg, a transistor or the laser): anything making use of a laser or a transistor wouldn't be patentable for ~10 years after the development of that technology. This may help prevent some stupid patents -- land-grab stuff around doing stuff with a laser -- but it also means that any invention that's mostly-done but missing something (like, eg, it'd work if only I had a source of coherent light) now has a 10-year time out on it, also, as it won't have been solvable for 10 years until 10 years have passed from the introduction of the missing piece.
You could try patching your solvability criterion to work around the "missing piece" phenomena but if you put a tiny loophole in next thing you know people will be driving a caravan of 18-wheelers through it.
Your proposal's criteria is also at the margins somewhat self-defeating, especially in the case of a trial in which a patent's validity is called into question.
The person defending it basically has to defend the patent by minimizing its novelty: all the constituents have to be old + well-understood and so on. So the ideal patent is minimally-inventive: it takes solves a known problem using well-known stuff in novel combination...but not too novel, as something too novel runs the risk of exposing you to arguments that the problem you solved wasn't solvable b/c solving it required too many of your own innovations.
The person attacking it has to attack it by maximizing its novelty: claim that the problem wasn't solvable for as long as you're claiming b/c it depended on sub-inventions and so forth; rather than being a minimally-non-obvious recombination of existing technologies you're actually inventing stuff, you see, which works against your patent's validity.
The 10-year period + commercial viability argument cuts both ways: on the one hand if it was solvable for awhile and was commercially viable you can use that as evidence for non-obviousness, but on the other hand your attacker can use the same facts to claim it either wasn't solvable before you went and invented stuff, wasn't actually commercially viable, or some other reason; you're making an overbroad assumption about what seems like reasonable assumptions for other people to hold about the invention process.
So you wind up with inventors forced to downplay the inventiveness of their inventions -- and shy away from overly-novel areas of inquiry -- and attackers overplaying the inventiveness of the inventions for which they hope to invalidate the patents, which scenario is comical but unproductive.