A printing press is always useful. Have your sleepers snoop around for a bit. The less effective ones should keep promoting liberalism though. Start training your skills. The crack house is a safe bet for security, and you can train stealth and disguise just fine in most places that require some sort of disguise to not raise suspicion.
FWIW, if someone lays low, their effectiveness tends to go up over time. Lay low for a year or so and you ought to at least get 30-40% Effectiveness. When Promoting Liberalism both is pro-rated by your current Effectiveness (50% Effectiveness means your effect on the issues was just halved) and reduces your Effectiveness in the bargain, having low-Effectiveness people promote you seems ineffective at best.
The Apartments provide as safe a place as possible to train Security. If you stay in the hall, the only way anything can go sour is picking a lock with an encounter right there watching you. So, don't pick doors with an encounter present, and don't actually enter any apartments. If your picker's current skill is 1-2, go to the Projects, 3-4 to the Uni Apartments, 4-6 to the Downtown Apartments, and after that you have a pretty good shot at any door. Wait until 8-10 to go after safes.
As for infiltration: the sweatshop accepts Naked as a disguise, typically has plenty of Cloth to steal, and Juicy machinery to smash; and Black Robes boost Stealth, are valid Courthouse disguises, and are fairly easy to make. Those are my two go-to places for training infiltrators. Factories are another good spot due to the melee-only Nonunion Workers, rampant Machinery, and comparative ease of making Work Clothes.
For money, have somebody commit credit card fraud to level up their computer skill, and make clothes. Expensive suits and dresses usually generate good income if you sell them. If you want to boost somebody's persuasion, have them solicit for donations. Gets you money and trains the skill.
Soliciting donations really doesn't generate that much money, though all else being equal it's fairly safe. But my 21 Charisma/21 Persuade Elite Liberal in an Expensive Suit still only makes $2-3/day soliciting donations. If you've juiced & trained the people with a few points of Street Sense, I'd recommend Selling Brownies--it trains Persuade, Street Sense, and Business, makes decent money, and provides a valuable good to the community. If the Death Squads aren't around, anyone with Agility 10+ can generally escape the Police.
Once you have a reliable income, have your squad members train skills at college. Law is good fro your leader (for an easy way out of a guilty sentence). It takes long to make it worthwhile, but once you have, you don't have to worry about your sleeper lawyer's skills for him at least. Have one or two of your most skilled members train teaching. Once that's high enough, you can easily and relatively cheaply pass on their disguise, persuasion etc. skills on your other squad members.
You could also get meetings with Lawyers (or, better, Liberal Judges) and talk about issues for months on end. High skills from whoever you meet with rub off on the Liberal over time. Takes months, if not years, but it's not like you're short on time and those can train Liberals up to the person's own skill. Teaching caps at (teacher's_skill)-1. I've found that Liberals teaching other Liberals get Teaching XP fast enough that I hadn't known there was a Teaching course at the uni. (Never looked for one. Teaching Politics is only $20/day.)
Make sure you don't go all out in crimes until you have a sleeper inside the police station and CEO HQ etc. Raids are nasty and a sure way to losing squad members. Your sleepers should keep you informed with enough time to get the hell out of your safehouse.
FWIW having more sleepers increases the chance that any one sleeper will issue a raid warning. I'd recommend 3-5 people inside the Police, along with any other place you'd be interested in advance intel. Same with sleeper judges: if you only have one, xe can't hear all your cases. Having four or five gives much better coverage. Exception is the sleeper Lawyer: only your best is available, but xe always is. If you don't like xyr stats, give xyr some easy cases (Vandalism, Theft, etc) to provide some XP.