I think you're addressing three different things at once here -not sure about "training to raid suburban homes" but if so that's not exclusive to the IRS; if you're an 1811 (criminal investigator, i.e. Special Agent), you go through tactical training alongside HSI, USSS, NCIS...basically every single law enforcement agency except FBI and DEA trains together. It's like the military: The basic training is done with a mix before they get sent off to agency-specific training, which is mainly classroom stuff on topics like learning the tax code forwards and backwards, money laundering, and other technical stuff.
They've been hiring criminal investigators for over a century now and only *now* is it becoming "controversial" because Biden and his friends are pushing for an expanded IRS (more on this in a second). What happened is almost certainly an ad that was poorly timed but no hiring announcement yet (note that 1811 announcements are hands-down *the* most sought-after announcements and there are a number of message boards and threads dedicated to tracking them from potential/hopeful applicants to current 1811s giving advice). As this is a position where one is a sworn LEO, this is a very competitive and difficult job type to get into. But CI *does not do audits* and never has: All audits go through what are called Revenue Agents, and only if the RAs discover evidence of criminal misconduct (like a business with a track record of consistently understating its income over several years) will the case get transferred. Criminal investigators aren't interested in getting into a drawn-out argument over loopholes or gray areas; they're looking for slam-dunk cases. Like a couple of years ago when they nailed the (now former) mayor of Baltimore for not reporting income from the sale of a series of children's books she was writing and selling (with one of her biggest customers being, totally by coincidence and surely not corruption, the Baltimore school district), or nailing the biggest union boss in Pennsylvania for corruption and tax evasion. I'd also note that all the CI agents *themselves* all get audited as part of the hiring process and then every single year thereafter.
Uh, no it's not. Like, it's one thing to complain about the IRS getting a ton of new personnel, especially since the states purpose is to hire more Revenue Agents, i.e. the people who do the audits and everyone loves to hate. And yeah, I am fully aware that this is mainly directed at screwing the middle class, like pretty much everything else Biden and his friends do. And complaining about this is a fair criticism.
Look, given the crap with Lois Lerner and her friends, being skeptical is entirely warranted (especially when the Democrats voted down an amendment to not allow this to be targeted at lower income voters) What's pissing me off is people claiming that this is going to lead to armed people shooting innocent taxpayers if they screw up, because some idiot somewhere took something out of context YET AGAIN and caused a stir over nothing. They're two separate divisions, and the armed ones aren't the ones you actually need to worry about unless you are, in fact, engaged in years of deliberate tax evasion that's cheated taxpayers out of hundreds of thousands if not millions of dollars.
And it's even more important to note there's a serious division in terms of points of view between field offices and HQs in Washington -for example, there's a reason that all the fiascos are being directed out of HQs rather than the local field offices, who generally hate this shit because it makes it harder to do their regular jobs.
Again, you're confusing two different divisions with the IRS. The LEOs aren't the ones engaged in that.
Also, the IRS doesn't handle hiring security guards: Those are all under the Federal Protective Service (which is part of DHS).
While I agree with the spirit of your post, USSS was shifted to Homeland Security in 2003, along with the Coast Guard and the Customs Service (though there was discussion of Trump and Munching moving USSS back to Treasury, which given the USSS' main job makes a fuck of a lot more sense).