Too many interesting ideas to comment on, so let me jjust share my story.
I was a really insecure kid, the kind of nerd who, partly because of my handicap, kids pick on most, probably. Well, this one girl Angela, was always such good friends with me, even took time to learn my made up songs and do silly stuff with me on the playground. We became really close freinds. In fact, I knew from my grandparents that that was an essential of marriage, & in an assembly once I even told a friend I was going to marry her, which brought laughter from those around us.
but, you know, I said if she didn’t marry me I had someone else in mind. I cared about her, because she did the same for me. And, when she moved away in 5th grade, and told me she always liked playing with me and such the day before, it was reallys weet. I felt loss, but just to know she like me too was something special.
And yu know, I have had girlfriends off and on since (I’m 34 now), but nothing can approach the deep friendship we shared. And, in a way, I think I loved her. Maybe more as the “friend that sticketh closer than a brother” type from the Bible, but I’d say I felt love. Maybe a little different from your 3 options, Dioptre, except maybe some of option 3, but i still care about her. You know that song "The Diary,’ by Bread? i think it really typifies how I feel about her - because I wish for her and pray for her all the sweet things that she would ever desire.
Ah, yes, to have loved and lost is far sweeter, because though I never got her forwarding address (which was dumb, but I wasn't a good pen pal anyway in 5th grade), I know someone cared a lot about me, and even though i had a great, loving family, that memory - true love or not - is always there, and helps me through rough times sometimes.