I think you are missing a key point of most of the Mental Manipulation spells: The target has to choose to take that roll, and there's a decent chance he won't notice. Then he has to spend his entire turn every time his turn comes up doing nothing but concentrating on repelling your suggestion. Your example has you casting the spell at Force 4 or 6, but what if you only need two minutes, and so can cast at Force 2? Assuming Spellcasting 6, your target won't even know there's a spell to resist without four hits on a Perception + Intuition roll!
So, you're trying to get your team into a club via the side door (the decker's already dropped the only camera on this side, so there's just one guard between you and the door). You have everyone - yourself included - wait in the car while you Influence the guard through the window. The guard, being primarily physical in nature, has most of his stats in Strength, Body, and Agility - and he put a decent amount (per your assumptions in question) into Willpower and Logic - leaving very little for his Perception and Intuition! The guard's looking at the big fancy SUV that just pulled up pretty suspiciously, and starts to reach for his radio... about the time you finish casting Influence with a suggestion of "You're expecting a VIP and his entourage to come to your door tonight; remember, no eye contact, attract no extra attention, and get them inside ASAP!" The guard stops reaching for his radio - what if this is the VIP he was "told to expect"? Six seconds later (after the spell becomes 'permanent' so you won't be busy concentrating on it while you're getting past him) - and you've got a full minute-and-fifty-four seconds left to just get out of the car, walk past the guard (who is averting his eyes, since the 'VIP' doesn't like to be looked at directly by the help), and get lost in the crowd before the guard might realize he was fooled.
At no point during the actual concentration time of the spell should the guard think "I should dedicate the next few seconds of my life to intensely concentrating to try to repel a mental invasion" - he still doesn't know there's a mage around at all, much less one targeting him with mental manipulations. The only time he should even consider trying to resist is the one time he's going to be too busy interacting with the guests physically to do so: if one of your team has to carry a big, obvious gun. When this happens, he should still speak with respect (and quietly, no extra attention on the VIP, remember?) and be easily brushed off with "Duh, I'm Mr. Johnson's bodyguard. You should have been briefed on this. Local yahoos..."
But, even with all that said, yes, you're mostly right.
If, say, you used Control Actions instead of Influence or Control Thoughts, and it became immediately obvious to the poor guard you were controlling him like a puppet (and his own turn became useless since he can't take any physical actions himself), then he would like spend every turn doing nothing but resisting you. And he'd get a handful of rolls to do so while you were busy making him throw away his ammo and give you his keycard.
Using Influence, your math is right, except that he doesn't get extra rolls if you give him a command he knows is wrong; he ONLY gets to roll if you do so (or otherwise realizes he needs to resist). If you're careful wording your Influence or gentle with your Control Thoughts, and use the bare minimum Force you'll need to get past that target (preferably without him "snapping out of it" after you're gone and realizing what happened, although that's pretty easy to prevent), that opponent should only get ONE long-shot roll to try to detect that someone just hit him with a spell. If he doesn't notice, he certainly shouldn't stop to spend two minutes of his life intensely concentrating on countering a spell he doesn't even know was cast in the first place.
