To start with the single coils:
No, the Irish Tours are not like the Fat 50's. I think they're in the ballpark of the BKP Apaches. The IT's are more or less overwound Mother's Milk, a little less woody, more bass, mids and a tad less topend.
A baseplate on the single coils can help to give weak and thin pickups a little more balls, but also enhances the highs. Personally I don't like a baseplate on the neckpickup because it gets quickly quite boomy. On the bridgesinglecoil a baseplate is often a good thing.
For the humbucker:
The VHII and Crawler are totally different pickups, except outputwise. The VHII nearly touches the output of the Crawler.
VHII: quite some bass for a hot PAF, good midrange, clear bright but not shrill topend, noncompressed so can let it scream when you dig in. Pinched harmonics a plenty. A very focussed pickup that imho isn't that versatile as say a Crawler. The split of the VHII in combination with the middle pickup is not as happening as the splits of Crawler/IT-combo.
Crawler: medium-output, fat, huge mids, great solotones also above the 12th fret, cleans up very good (jazz/rockabilly possible) but growls in a unique way when pushed. Versatile pickup with still a enough PAF-pedigree to place it in the vintagehot department, but can handle heavier styles (maybe not the best metalpickup) quite well. Split as a tele-esque quality to it.
I think the Crawler excels in bolt-on alder and (swamp)ash guitars.