Yeah, they're just randomly calling stuff different things. There are some that match or are close (they like adding 'u' to words like Mold and stuff, but if they're going for British-y, then that's one way how).
I have no idea about DQ7..I've only played it in English. I've played the others in JP though, and English if they came out.
Let me find the list..weapons and items were kind of close, but still off; nowhere near as off as some other things, though. Not one town/place in the demo is called the same thing, and none of the NPC's have the same name so far, either. The main characters are the same though, except for Kukule -> Angelo.
Here we go, with some additions.
Spells
JP Name / US Name / Old US Name (if applicable)
Gira / Sizz / Firebal(l)
Merami / Kafrizz / Firebane
Mera / Frizz / Blaze
Hyado / Crack / IceBolt
Riremito / Evac / Outside
Hoimi / Miniheal / Heal
Behoimi / Mediheal / Healmore
Ru-ra / Zoom / Return
Rariho- / Snooze / Sleep
Bagi / Woosh / Infernos
Kiari / Squelch / Antidote
Io / Bang / Bang
Kiariku / Tingle / NumbOff
Sukara / Buff / Upper
Sukuruto / Kabuff / Increase
Piori-mu / Acceleratle (how it's spelled in the demo) / SpeedUp
Monsters
Suraimunaito (Slime Knight) / Slime Knight
Hoimisuraimu (Hoimi Slime) / Healslime / Healer
Oomedama (Giant Eyeball) / Winky / Giant Eyeball
Jinmenju (Human-Faced Tree) / Treeface / Evil Tree
Jaiantobatto (Giant Bat) / Fat Bat / Jumbat
Pu-kupukku (Hell if I know) / Pan Man
Riripatto (Lillipat) / Bodkin Bowyer / Lilipa
Kimera (Chimera) / Chimaera / Wyvern
Dendenryuu (Thunderous Dragon, according to Bebpo) / Jargon
Suraimubesu (Slimebeth) / She-Slime / Red Slime
Waraibukuro (Laughing Bag) / Bag o' Laughs / Trick Bag
Burauni- (Brownie) / Brownie
Baburusuraimu (Bubble Slime) / Bubbleslime / Babble
Rinrin (Ringring) / Dingaling (I think)
Abareushidori (Violent Cow Chicken) / Bullfinch / Brahmird
Zapan (Zapan) / I forget, something totally different (boss of the Waterfall Cave)
Towns
Torapetta / Farebury
Rizasu no Mura (Rizas Village) / Alexandria
Some names are closer than they were to the old US name, sometimes the old US name was closer and now it's far off.
NPC's are different too, like Yurima -> Valentina, Kira -> Emma, etc. I'd go and type them all out if I were to play the demo again, but more or less it seems that monsters, towns, and NPC's are just totally different and out-of-the-blue, but some skills are rather similar, as are weapons/armor/items. It just isn't the case that whoever is working on it is doing a change from the old US names to something more like the original name; they're just going with whatever sounds cool or something. I dunno. It's far from an 'improvement' in the aspect of changing to be closer to the originals.
Is it something to get seriously pissed about? Depends on what you are looking for. If you never cared in the first place, it wouldn't matter (and I doubt you'd read this post

). If you wanted the familiarity from the last games you've played in English then you'll be hard-pressed to do so and will have to learn what stuff is called now. If you wanted a 'closer to the original than before' you'll be just as hard-pressed.
More or less, you seem better off to not give a crap. This game is just as "off" as any others if you are still looking for that 'very faithful translation of stuff'. You just have to forget what you've been raised with if you have played any earlier versions of any games in the series.