Yeah, Seiken Densetsu 3 is called Seiken Densetsu 3 for a reason. The first Seiken Densetsu was some game on gameboy called... Final Fantasy Adventure, I think, and Secret of Evermore is a completely different game/story...
Yes, the Chrono Trigger soundtrack is definitely worth 5 pounds... I paid about $30 USD when I bought it... damn, that was a long time ago too. And Seiken Densetsu 3 has some kickass music as well. So do a lot of other Squaresoft RPG's. Right now, I have the following game soundtracks: Chrono Trigger OSV, Chrono Trigger Arranged Version: The Brink of Time(jazz remixes of about 10-15 CT tracks, pretty cool actually), Chrono Trigger OST(yes, there's a difference between this and the OSV. This contains ONE disc that has the new arranged versions of the CT music that you'll find in the cutscenes on the Playstation version of CT), Chrono Cross OST, Brave Fencer Musashi OST, Seiken Densetsu 3 OST, Final Fantasy 7 OST, and Final Fantasy 9 OST. I'm sure part of the reason why I love the Chrono Trigger music so much is because it was part of the game, but at the same time, the music helped to make me like the game too... it's not really entirely one or the other, and I think I'd enjoy the music even if I'd never touched the game. I don't know why, but Time Circuits(steel drum music you hear in Zeal) just sounds so damn good. Whenever I listen to it, I feel really calm and at peace, like i'm meditating or something... it's fricken crazy.
*for those of you who don't know, OST = original soundtrack, and OSV = original sound version(really the same thing, but for some reason they chose to use version instead of soundtrack for chrono trigger....)*
So, Kokonut Helmut... you got inside Arris Dome and can't see anything... first of all, I know this is on an emulator because the real game doesn't have that problem. Now... if you're playing it on osnes9xGP 0.3, under "hack options," there's a bunch of background switches that you can turn on and off. I think it's BG01 or BG02... don't remember for sure though... just experiment and turn one of them off. Then the fog will dissapear completely. Unfortunately though, the text is also part of the same "piece" of background as the fog, so whenever you talk to someone, you'll have to go into the menu and put the background back on and switch back and forth. A pain in the ass, I know, but there's no other way to do it that I know of, and you definitely don't wanna miss out on any dialogue, right? if you're not playing it on a GP32, or you're using a different emulator, as far as i know, they all have some kind of option to eliminate some part of the graphics. Look around, find it, and try turning off background layers until you find the right one.
Also, to answer your other question, kokonut, Chrono Trigger is linear, but at the same time it's not... it's kind of like all the final fantasy stories that I've played in that there are certain things that you must do to make the game progress, but you'll get to a point where all you really have to do is defeat the final boss. However, you're also given the option to go on a bunch of small sidequests... which you don't have to wait until the very final stage of the game to complete... Well technically it is the "final" stage of the game, it just doesn't feel that way. But the cool thing is... once you beat the game, you can start what's called a New Game +, which starts the story all over again, but your characters have all the items and weapons they had in your previous game, and they're the same level they were. You also have the option of beating the game again at any time you want. Depending on what you've completed in the story so far, you'll be treated to a different ending, and there are about 11 in total. Even if you complete every single sidequest, there are still 2 different endings you can get, depending on what route you take to fight the final boss. Also, depending on a few key choices you make, some small modifications to those 2 endings will occur. It's really quite cool, and I hope you enjoy Chrono Trigger at least half as much as I did.
Well, it's time for bed now, so I'm gonna go get a bath and then play Chrono Trigger in German until I can't stay awake anymore.