I, personally, wouldn't say that the things you've mentioned are sinful, according to the Bible:
the hug~which is an act that can mean anything from 'I've missed you!!' to 'I appreciate you for who you are' to 'I'm sorry you're going through that' etc etc..
the hand holding~which is an act that can symbolize anything from 'I don't want you to fall on the ice, so hold onto me for support,
mom'

to 'you're my boyfriend & I think you're pretty sweet' etc etc.
the kiss~ah yes...are you referring to a holy kiss??...
but really, I think that people who've told you these things have
meant well, Lovesherald b/c in some ways, that stuff
could lead to other acts, which may or may not include sexual ones. I think the people that have told you that such things are 'sinful' are perhaps just intending to mean that it may not be moral to act upon these things, considering that the other person may not be strong enough to resist you, sexually..
or that he just wouldn't be clued-in & understand that you aren't interested in more than what you've just described. I dunno, though...I'd be interested in seeing what your responses will be...and if someone could point to a certain peice of Scripture that supports their claims b/c if there is such a verse (or more than one), I'd love to check them out.
