That's for them to say, also Crafty pretty much summed up my viewpoint on the issue.
One possible alternative is making a slime farm and then selling it on, the slime market could be very profitable for people who wish to create shops.
It's important to remember too that Slimes are rare enough in SP too.

@Blackfish_ Yes. ive check the firewall and its on. should i turn it off to make everything works again?

and i dont have any anti virus in my computer btw

Well I wouldn't suggest turning it off permanently but turning it off for a few minutes to test if it works would be a good thing.

@Blackfish_ negative. ive tried the 1.11.1 version and it still shows extremely lag or even won't let me login in to the server. The problem is with me or the minecraft server?

It sounds like your computer is blocking the minecraft authentication servers, do you have an anti virus or firewall running ?

Have you tried using previous versions of minecraft, like minecraft 1.11 ?
There's plenty of servers who have not upgraded to check this, it will help establish whether it's a network or client issue.

@Sofatroll Ye, but no way using it cause we are all awavare of the fact that necro-posting is the worst of all crimes!

That's not a fair assertion, the worst of all crimes is hacking or damaging the server hence the perma ban for offense.
The punishment for necro posting being a light warning and maybe a lock is very light in comparison reflecting the lack of severity, we don't like it however since it's spammy and 99% of the time does not actually add to the topic or just seeks to cause an argument.
The only people making a big deal out of it are those complaining.

Request completed, thread locked.

To be absolutely clear you request a ban ?

Adding something relevant to a thread is not necro posting, the problem is the vast majority of revived threads are due to some joker putting in a one liner like "lol" or I agree which has no relevance and the event has likely passed. That is not the case here.

While I would wait for an admin or crafty to respond, I don't believe such a thing would be forbidden given it's benign usage.

I've found a number of slimes, so they aren't that rare.
As for the villagers, we tried to stay away from non vanilla villagers this map and I think it should be kept that way, the prices on it are verylow too considering slime is a valuable resource even in single player.

If someone doesn't want there deaths shown then that's up to them as far as I would be concerned. I mean why do you really want to know ?
You can always count the top deaths, manually with ease.