Language barrier prevents making friends of a similar interest, and it's a serious problem with the over-take of so many non-English speakers, in a primarily English-focused social game. So many non-English speaking players near the starting area is alienating a more targeted, appropriate audience. You can see the effects of this already in the game, and it's only bound to get worse until something is done about it. Good luck to those trying to replace their decreasing buddy list without picking up Portuguese/Spanish/Filipino.
Towering used to have a mild incentive with it's "1k hats" as a prize for holding down towers for 1,000 in game hours. But, with the long-since removal of it; there is little incentive for players to hold down forts. I've personally been able to over take a tower and basically just go AFK only needing to hit the flags decreasing health off-and-on for over half an hour at a time. Towering is dead, and I think the removal of towers is hurting the game more. I understand the logic of "If not many people are towering, removing some of these towers will increase population/activity of those areas", but I think it's sending the wrong message to players. I think it's sending more of a message of "this is a relic, and these are going to be phased out." with the constant removal of these competitive, PKing areas.
PKing has never really had any incentive for it, until the seasonal rewards were added. The brief rewards of PK specific mounts weren't a lot in my opinion and barely a driving force for keeping players interested. PKing doesn't get the same treatment as sparring does within the game. You're not getting currency to purchase new cosmetics, furniture, mounts, etc. In-fact, I think it's generally seen as just a mild annoyance rather than anything fun or *skillful. (in terms of general playerbase/support for the activity.) Towering is closely related to PKing so it, at the time, probably didn't make a lot of sense to add rewards for the activity when it was just a natural byproduct of keeping a tower.
Sparring has been going down hill for years now, and although the specific currency did make a mild resurgence in the activity, it was clear to me that this wouldn't hold attention for long. Sure, we have things like the seasonal Guild Sparring Tournament, but this is only interesting for players who haven't won multiple times already. It's nothing more than exclusive hats and bragging rights for the season. But if there is nobody to brag to, who cares? That isn't to say that the competition is flawed necessarily, but it does present a problem. The bragging heavy aspect of GST/Sparring is also a great issue. It can be a driving force behind someone wanting to spar more to become better at it, or it could be a complete turn off to those who wish to do it more casually. I personally find it a huge turn-off when I go into the spar room and see hardly anyone that speaks English, or the ones that do just gossiping/trash talking each-other more than sparring. Sparring in-general also heavily relied on known-players who did the activity. Sparring was seen as a cool activity because that's generally where the cooler players hung out. Typically the sparring crowd consisted of people who've been around for a long time, and that had an appeal to new-comers and other oldies alike.
There really isn't a magical fix all solution to any of these problems, it's difficult. We all know the NGS is coming, but it's tough for me to say at this point whether it will have anywhere near as heavy an impact as people and staff alike are hoping for. I personally know it'll at bare minimum create a resurgence in active players, but will it be as special as everyone is hoping for? Well, we'll just have to wait and see I guess. It's going to have to bring a lot of "firsts" to iClassic.