Not to mention that even the definition of truant is kind of a stretch, since in the incident in question, her transgression was being in a different part of her house. Her own complaints to Morgase suggest that Rand might very well be the first person with whom she has been that close to alone. If everyone else she has met has been in the company of guards and servants, making out was probably not on the agenda. Note too, that even in this incident of delinquency, she could not shake Gawyn's company. It seems really unlikely she would have got that far away from all eyes, given what we know about her supervision. We are talking about the ONLY heir to the throne, and the first hint that she's with a stranger bringing a bunch of guards swarming. Unless Elayne's wildness included an indifference to observation completely uncharacteristic of anything we've seen from her, fooling around seems unlikely.

I don't actually recall any sort of hints, one way or the other, about any of those three, aside from assumptions based on the stage to which Rand's and Egwene's relationship had progressed. Likewise, your assumption of Elayne's experience seems to based on assumptions of opportunities she would have had available. When she and Aviendha are talking about that stuff, Rand is the only reference point she cites in her own experience. Not, 'she enjoyed having it done too,' or 'enjoyed when men/boys did that too' but "when Rand did that too." If you're really fixated on the idea that Elayne had pre-Tower boyfriends, you can find reasons why she would specify Rand, but given what we know of her sexual reticence and protected circumstances, I'd call it 50/50 at best that she'd got to first base before.