I've been using worldborder to preload chunks and I've had 3 issues

When I execute the order to start preloading chunks, in the console it starts appering three quite common messages related with mods that create things over the world. Do I have to worry?

1rts one

[Server thread/WARN] [FML]: LLibrary loaded a new chunk [-30, 17] in dimension 0 (overworld) while populating chunk [-29, 18], causing cascading worldgen lag.

[Server thread/WARN] [FML]: Please report this to the mod's issue tracker. This log can be disabled in the Forge config.

2nd one

Chocolate Quest Repoured Mod loaded a new chunk [4, 36] in dimension 0 (overworld) while populating chunk [5, 35], causing cascading worldgen lag.

[Server thread/WARN] [FML]: Please report this to the mod's issue tracker. This log can be disabled in the Forge config.

3rd one

[Server thread/WARN] [mca]: No skin found for profession: `mca:bandit`. A random skin will be generated.

Thanks in advance!

Edit: I've a new problem. This one's in red so idk if I shoud worry

[Server thread/ERROR] [Minecraft]: Block at 728,10,-392 is MOB_SPAWNER but has net.minecraft.tileentity.TileEntityChest@69253a0e. Bukkit will attempt to fix this, but there may be additional damage that we cannot recover.

And how could I enter to the mod issue tracker?

And, as for the skin problem of the MCA, how could I fix it?

thx for answering