Get access to the cimetery (sp?) in the monasty ... i went there already lol (using th roof tops hehe) and got all the loot etc in there (also for a quest) but the guard still wont let me in. At one point i refused to give him the stew , so he told me off lol. I tried jest and everything no go.

You do realize there is no mainland anymore as the Titans destroyed it? This island is the only one left that isn't burning(yet).

the red barrier in the hidden library in the monastry, obviously i need a scroll for it, but where/who sells/has one ? i clicked it and it shows me touching it and mumbling about it, i then went to talk (well tried to) too all the masters etc and nothing.

There's nothing interesting in there, just a chest and a bookstand, if I remember right. You need a "destroy magic barrier" scrool, or something. You'll get it from Cyrus, at the lizard temple (the druid quest).

Anyone did the part where the monastery is invaded by lizard intruders? I can't find one of the wizards, I think it's the one that used to stay at the gate, can't remember the name. I looked everywhere for him...

Those are ley lines aren't they, not hard to imagine what such a impact would cause on the landmass.

Aric at the monastery

Wait till you meet the lizard people. You'll throw the keyboard out the window, that's how bad they are.
As for the force field, read my post above.

Aric has a magic sword, you have to trick him first into using a bad sword etc, ask around ^^

Does it show that in the movie? all those blue lines? is that supposed to depict the landmass dissappearing?, I thought it was to show the dark energy that was unleashed and "woke stuff up" in various parts of the world.

Kinda mentioned above but I saw the magic lines as following the "earth" ley-lines, if those are affected by such a severe blow as that impact then I can imagine there wouldn't be much left of the main continents and mainly smaller islands, just how I interpreted it, magic is believed amongst some cultures to flow along such lines so I simply put it together as a sort of "armageddon" event.

EDIT: Plus you see the world rip and tear as those temples ascend from the earth though it doesn't show in what scale this happens so again it's down to user interprention of the story, just as the backstory for "nameless" is, as is very common in Piranha Bytes games or rather the Gothic series.

when i beat up Costa in harbor city he still doesn't give me gold what do i do?

He's in the big library. You can access it trough a secret door in the small library (where you meet that guy who asks for the Wisdom in Combat book).