I'm pretty sure the Home Office and the Treasury won't be taking memos from the Leave camp, either way; particularly re spending. Rhetoric is all well and good, but if you aren't putting the needed funds in, you aren't achieving much, are you? As per my questions above, what gives you the great confidence you seem to have that the cuts to the Home Office will stop and reverse in Britain outside of the EU? It would need to expand, if anything, given your requirements.
Hence why I'm puzzled by the frequent, sweeping promises thrown about by the politicians on the Leave side, with the least power to deliver them, or indeed be held accountable for them. And precisely because we do get what we need, in a flexible, red-tape-free way, plenty of people here have developed a huge chip on their shoulders; ironically through hearsay and rumour rather than anything substantive, conflating all and sundry.
Additionally, even under the current spell of May's reign at the HO, the claim that we are somehow shafting the non-EU migration level is gonads; look at the actual numbers and the trends:
http://www.migrationobservatory.ox.ac.uk/briefings/non-european-labour-migration-uk
http://www.ons.gov.uk/peoplepopulat...sticsquarterlyreport/february2016#main-points
Furthermore, if the OBR forecasts are on target, why take a risky leap out of the EU if the migration levels will settle naturally (effectively halved) by 2021 anyway?
Lastly, with one's preference for white, native-English-spoken non-EU migration, one is yet to demonstrate the likelihood of Assies, Canadians, Americans, et al, to come here to build walls, wipe bums and pick fruit.
If that's your common EU migrant picture that is, which again is about as statistically accurate as snow at the equator! But do go on.