jrdioko wrote:"Onnellisena tiedän, että huolimatta olet vielä ystäväni."
"Onnellisena tiedän, että
kaikesta huolimatta olet vielä ystäväni" is possible but the "Onnellisena tiedän" sounds a wee bit incomplete... Dunno why. "Olen onnellinen tietäessäni" would actually sound more complete, however, is admittedly longer and less poetic. As said, your suggestion is possible, tho.
The difference between "onnellinen" and "iloinen" - a very good question! I never actually realised it was much the same word in English!!

As GaffiGubbi said, the difference, however, is marked in that "onnellinen" is actually "happy" as in "happiness/content" etc.etc. It's a slightly more permanent state of mind whereas "iloinen" is more "cheerful". You can be "iloinen" one minute but "surullinen/pettynyt" the next as opposed to being "onnellinen" which tends to last a little bit longer...

Well, not always but anyway.
Did that make any sense...??