The problem with using the dice rolling function, is that I can preview the dice roll results, and if I don't like them, I can delete the script, re-preview my post to clear the cache, and then re-roll the dice until I get the results I want.
Not that the concern isn't legitimate but I for one am of the opinion that anyone who would cheat is only cheating themselves and would be willing to leave it at that. If a person is going to cheat they will cheat whether dice script altering is possible or not, I think the concept goes beyond simply cheating and in to good sportsmanship. I think it's safe to presume anyone who is going to partake is partaking from a place of love of the community/story aspect of the game and not to simply win at any cost.
I think the goals/agenda of the game could be structured as such to help get away from any carnal motivations for that as well. If we are looking at something more Story/RPG/Character driven, then we aren't talking about large scale territory and resource conquest, we don't need to be bothered with constructions and stock piling and such, it all becomes part of a story mechanic.
Some rolls, perhaps outside of combat when affecting characters ability to "level" or improve and such could possibly be handled by a GM as well. Could also consider GM handling combat rolls, but I think that removes some level of hands on feel for players
Another thought is a decoder system that is revealed only after each roll. In this way, even if a player chooses to look at die face values with preview before posting, he won't know for sure what the values will translate in to until the GM decodes it with a decoding roll. Basically it'd go something like as follows. . .
1) establish 2-3 set legends/keys for decoding rolls. . .
1 = hit 2 = hit 3 = miss 4 = miss 5 = action 6 = action
1 = miss 2 = miss 3 = action 4 = action 5 = hit 6 = hit
1 = action 2 = action 3 = hit 4 = hit 5 = miss 6 = miss
2) a player is attacking something with something else. . .
player elects to attack with something that uses 3 attack dice, so his roll would look like this. .
Rolled 3d6 : 3, 2, 6, total 11
but even if he sneaks a peek, who knows which of the 3 decoding legends will be applied.
3) after a player rolls, a GM makes a decoding roll immediately after that simply arbitrarily chooses which key to choose 1-3 . . .
Rolled 1d3 : 3, total 3