In general, starvation mode s basically a myth, so you're only "cutting too low" if your lifts are dramatically decreasing and you think you're losing muscle as well as fat. For 6'1" 191lb I don't think you actually have that much muscle mass to start with (It's absolutely fine to cut before you bulk, you've gotta be comfortable gaining weight) so I would say if you're not getting light-headed and the things in your life aren't getting affected by how little you're eating, then you're doing fine.
Basically, yes! The problem is that those calorie calculations range from inaccurate to wildly inaccurate, so I would make sure you only use 75-80% of the calories you've 'burned' if you're going to eat them. I tend to use it to make sure I make up for fuckups in my diet (thinking something is only 100 calories when secretly it's 600, that sort of thing).
You're fine the way it is now. You should be gaining strength on a cut if you're still on beginner gains. Remember those TDEE estimates are dodgy, too, particularly if you're a couch potato (like me, haha). I'm cutting on 1200cal with a TDEE of 2400 (supposedly) and I'm having the same experience (first time back to strength training in 1.5 years).
You shouldn't worry about having too low a calorie count. You'll know if it's too low - there's a lot of information out there about "eating too little" and a lot of it has to do with the culture of being overweight and too lazy to do anything about it. Unless you're training for a competition, don't worry about eating too little - those dudes are on 600 calorie diets for weeks and make sure they don't drink any water in the days before an event so they're as vascular as possible, sitting at like 6% bodyfat - THAT'S unhealthy. The average joe like you or I are going to be fine, even if some days are just coffee and a turkey sandwich.
The initial few weeks you'll see a big drop in weight, and a lot of it is water weight. Basically, a shitty diet -> lots of sodium, lots of sodium -> body holds lots of water. A good diet -> less sodium in your body -> body holds less water. Your next few weeks will probably be slower. If you want to lose weight faster, don't be afraid to even lower your caloric intake a bit, so long as you still feel like you have energy for the day and your strength isn't being destroyed.
Re-reading your post now:
Everyone hits a plateau, it has nothing to do with losing weight too fast. They last for a couple of weeks and then are defeated by physics, they're nothing to worry about.
Yo-yo effects are also fine, particularly since you're going to put on some aforementioned water weight from your change in diet. And then you'll be on a bulk anyway, so it's a good thing! A yo-yo effect, again, isn't a consequence of losing weight too fast, it's a consequence of someone who has been on a celery diet for a year finally being able to eat a real diet again but not knowing how to eat to their maintenance calories properly and stuffing their face with coke and burgers until they're fat again and blame their personal trainer.
For your weightlifting, you should look into Starting Strength or Strong Lifts and not focus so much on the weight, but get your form right. They're not long routines and high-weight, medium-volume routines like SL can be explosive for beginner gains when you move into a bulk.
Phew! Good luck with your cut!