As someone who drips exclusively (out of necessity first, and just because it's so easy and care-free now), I'll address some of your points:
- If you over drips it leaks.
Depends on what you drip with, the size of the wick... If you drip with an atty that has a side air hole, then yes, it may leak if you put down your mod hole down. Not so with a center hole, through the 510-connector vent. But ultimately, it's all down to habits: me, I drip 10 drops in my atty at a time and always put my mod down hole up. I never think about it. It just happens, just like you would never put a cigarette down with the burning tip out of the ashtray. And I never put my mod back into its carrying case with the atty full.
Also, if you install a long wick, it holds more juice.
- if you still have juice in it and place the mod horizontally it leaks.
Not with the air hole up it doesn't. Again, it becomes second nature. After two days, you never think about that sort of thing no more.
- If you forget to drip and fire it you get a dry hit.
You quickly learn when it's time to refill. There's that funny taste that tells you the next toke will be bad. When you're used to it, you can even tell when you need to do a full 10-drop refill, or just 8 drops for instance.
- it's not "plug and play" if your coil goes bad you can't replace it on the go unless you carry your building kit with you.
I hardly ever find myself in a situation when I absolutely need to rebuild. The worst that happens is, during the day, the flavor starts tasting "muted". If I really can't live with the performance drop, I dry the wick, do a dry burn, then that gets me at least through the rest of the day. Then I rewick/recoil in the evening. Worse comes to worst, bring a pre-built coil/wick with you. When I travel abroad, I carry 5 to 10 with me in my mod's carrying case's side pocket, depending on how long I'm away from home for. But I usually don't need more than one or two.
Really, at the end of the day, dripping is only a matter of training your hands and your brain to go through the routine. Once it's well and truly ingrained, there's nothing special to it. You just do it, is all. It's really like fishing a cigarette out of the box, lighting up, looking for an ashtray, using the ashtray this-and-that way, holding the cigarette this-and-that way, flicking the ash... you don't think about it, you just do it on automatic. Well, it's the same thing with dripping.