1) For most people id say your "first impression" is usually very spot on if youre paying attention to the right things (personality, intelligence, humor...). Although it depends environment its in, ie personal or social..
2) In my experience, its almost always worked for me over 10 years. Well until the last one... 4 years strong with my ex-fiance and it ended very abruptly, at a time where i needed her the most. However, looking back i guess i can see she wasnt ready for everything i had going on (career, new state, wanted family)
3) I love a chase and a challenge, its makes things fun. But that was always just for casual dating, besides my ex. I hope to find someone as ambitious and shares the same views as me.. Ill pursue a girl to the point where i feel like its 1) not worth it or 2) shes just not into me