I agree with the reservation that making a special case of the latte stand and park would tend to defeat the gameplay benefits of making the change in the first place. I'm still a bit concerned with what Ringmaster mentioned about making sure this functionality is clear to the player, though.
About the latte stand and park, two trains of thought occur to me for limiting their appeal for grinding while still giving them unlimited passers-by. They're not necessarily mutually exclusive, and in fact the first tact would certainly be improved by the addition of the second.
First, make the nature of the environments alter recruitment mechanics. E.g., in the park most people you meet will have their true profession masked à la CCS members. That Doctor isn't listed as a Doctor, but as a Jogger or suchlike. This still means you could just recruit everything on two legs and judge their worth back at the safe house, but it'd act as a somewhat effective deterrent to grinding, anyway. At the latte stand, people are bustling in and out and just want to grab their drinks and go, so slap on a large brushoff penalty to talking about the issues. This latter is more problematic, since the logic of "inappropriate venues" applies even more strongly in some other environments, but still.
The second tact would be to make recruit-grinding there riskier early on. As these locations have no value beyond recruitment... place a time limit on how long you can stay there before you start running the risk of getting arrested for loitering, disturbing the peace, walking while Liberal, thoughtcrime, whatever. How long you have before the Man starts hassling you could be tied to one or more issues (e.g., free speech and police behavior), so as you liberalize the country, you can get increasingly unlimited access to these areas to fish for that one specific Liberal you're lacking.