In case anyone comes by...
===| Things solved and how : |===
I managed to remove all job requirements in skills. It wasn't complicated, it is in 3 steps :
1) I removed all values of the column 35 in LIST_SKILL.STB ,
2) copy-pasted it to the client,
3) in the dabatase, in skills_data, there is a column "class" where values are like "62|0|0|0|0", i've put the first number to 0 in the whole column.
(if anyone wonders, I figured out :
41 : Soldier
42 : Muse
43 : Hawker
44 : Dealer
61 : Knight
62 : Champion
63 : Mage
64 : Cleric
65 : Raider
66 : Scout
67 : Bourgeois
68 : Artisan)
I managed to remove the weapon requirements of some skills (I didn't want to remove them all, some wouldn't make sense), similarly, by removing at the corresponding rows the values of columns 30, 31, 32, 33 and 34 in LIST_SKILL.STB and of column "weapon" in the database in skills_data.
I changed as well the stat points earnt / level and skill points earnt / level. It's in WorldServer\playerfunctions.cpp , you'll see there is everything about leveling up.
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===| Problems I still have |===
My previous problem is still here - I can only launch WorldServer via the "debug" button in CodeBlocks.
What I don't get is that I thought I was using the same ROSE version than the one PurpleYouko's website shows skills for, and not at all, it's an old one where each skill has a level requirement - and skills are way less fun.
Any hint where I can find that other version? <- I've found some links provided by PurpleYouko. I'll see if I have faith to start all of that work on those other versions.
I'm afraid I'll have to do all that work again if I manage to find that version. Oh well.
Another thing bothering me is I can't seem to be able to open correctly the 3DDATA.VFS files, even with the universal VFS extractor, even when telling it the index is for TRose. So, I can't change again those HP bars, like I used to do some years ago...
Any reader is welcome to help, anytime. I'll come here often in next days, months and years, probably.
edit : also, the mobs NEVER drop equipable items, and while the drop rate and zuly rate in list_config in the dabatase seems to function correctly, it seems it's not the case for the exp rate. I'll investigate and edit this post as long as I got no answer.
I noticed a KTRose NPC at Adventure Plains. What the heck is my rose version? O_O
edit : it seems the column "map" isn't doing anything in items_drops in the database. I tried putting a probability of 9500 to an item supposedly dropping in Zant map, and drop rate of 30 to have tons of drops, while the min and max levels are 2 and 255 : lots of drops, 0 of such item. That could explain the lack of bird feathers as well as of all equipable items.
===| Other server&client |===
edit : I probably managed to launch the very last KTrose versions of the servers, from PurpleYouko sources, but I can't find how to build that client, the one of the WibbleWibble repository. I tried random things like using the old client while copying over tons of new files of the new client, I got lots of errors of DLL that I fixed by simply copying the corresponding DLLs, but then TRose just closes without any error.
What client should I use with those new servers?
edit : I tried as well the 2015 client, but it does 2 strange errors (though we hear a loading music), something like "file 3Ddata\\junon\\list_cnst_title_jzp.zsc open error", then crashes. As it seems the server part is working (which I could really only check with a client...), I'd really like to manage to get a client working for it.