Those lips are perfect. Far better than lip injections. Women have this notion that guys want big lips, umm, no, most of us don't and certainly not injections. We just want your normal natural lips. Yes there might be a guy or two out there that likes "full" lips but if a woman happens to have them naturally. Injections just make women look silly.
It depends on how they look on the entire face - if they suit the other features it's attractive, if they don't, nah. Personally I'm not a fan of super thin lips because I find they they don't really suit any face but yours still seem fine.
The lips in those pictures don't look bad at all. Personally I am not into thin lips but they are not unattractive to me. In other words I'm not gonna dislike a girl just because she doesn't have the lips I like best.
Those lips look very kissable. And i am sure a lot of other girls and guys would think the same. Its not something to be insecure about as big lips dont suit everyone i sure would look silly if i got my lips bigger even though sometimes i wish they were a tiny bit bigger.