You are certainly right about different opinions in this matter
I just can't imagine it, because he seems so overwhelmed after their first kiss. The physical intimacy must be something rare for him, as he can have the emotional intimacy with his spirit friends too. Also I know it works for me like that and I found myself amazed again and again how similar Solas acts to how I would in his situation, how he talk in ways I found myself talking to friends etc... Probably that's why I can't romance anyone else in that game^^
After hundreds of years alone I assume it's hard not to be overwhelmed
Still, he seems (dunno, just my personal observation) to be overwhelmed only in a sense that he was so attracted to her, that he couldn't stop from throwing himself at her and sweeping her off her feet, and only seemed to tear away from her after reminding himself that they shouldn't (for whatever reason), rather than in any way that suggests he's overwhelmed by kiss itself or lack of experience in these matters.
In any case, IMO, it's hard to achieve same type of emotional intimacy with spirits as a person can with another 'real' person. Solas mentions from time to time just how lonely he was for a very long time, which seems to confirm that it's indeed different - majority of spirits aren't as complex, personality-wise. Only more powerful spirits - like a very old spirit of Wisdom whom Solas befriended or Cole - gain enough of sentience and complexity to develop personality and capability to grow, mentally and emotionally - and even then, they differ in their way of thinking compared to Thedosians (Cole gives us great insight into this).
Therefore, while Solas has definitely befriended a lot of spirits and treats them with respect, it's likely very rare for him to find a - nomen omen - 'kindred spirit' or a soulmate, with whom he can share a deep emotional bond. It's possibly even rarer than - dunno, maybe in the past, long before his slumber - finding moment's respite in arms of attractive elves... I mean, SOMETHING has to explain that smoothness of his >.>'
I am curious: Does anyone know what happens if you do the well of sorrows but never talk to Solas again? Does that let you finish the game still in romance with him?
I'm too much of an OCDish completionist to even try, but considering that the last romance scene is necessary for Solas and Lavellan lock their relationship (ironically!) and his tarot card to change for a romanced one, it may be that the game won't count the romance as finished or continuing - I don't think I'd recommend trying that, especially IF we get the DLC with conclusion for romance(s), because I don't think the game would recognize it.