Just thought I'd take the time to give some suggestions, I understand we are still at early stages but hopefully the developers can at least get some help from these, or even make them better.
Skilling has always been a huge factor for many successful RSPS' provide user's with a goal, and your sure to have them grind for day's to be the first to reach it, If we were aiming to be unique... to set us apart from the generic RSPS, we need to offer the skilling players something other than clicking on stalls in edgeville to get mastery thieving, or skill capes that end up collecting dust in your bank because they are worthless, achieving mastery of a skill should be a big accomplishment, something that other players will look at in awe, below I shall list any changes I believe could be beneficial when it comes to skills.
Thieving - If we aim to be different, we need to amend thieving, typically one of the first 99's every RSPS player get's as stall's can be found at home and all it takes is an auto-clicker to master it, I believe removing stall's and replacing this with something... different.. and potentially harder will be good for the reputation of this skill.
Examples, pickpocketing villagers in a busy market square, along with stealing from market stalls, giving the people in that market, the ability to catch you and not attack you... but to call guards.. who will have the ability to jail you for a small amount of time, this way, your not just stood there spam clicking, you'll have no choice but to run if your seen.
As we want it to be similar to RS, maybe add small chances of obtaining gear to which will lower the chances of being seen, and a more rare chance of a pet.
Farming - We could go crazy with farming, and potentially link it in with construction, giving us the ability to build a garden / allotment / farm at our POH, (I will also be suggesting a lot more for construction) and potentially expanding what exactly we can grow, with a high level of farming, this could give the player an ability to grow things simply for decoration. Again, farming should offer a small chance of obtaining equipment to prevent disease / quicken crop growth, and the notorious pet.
Construction - This skill is very under used in many RSPS' to be able to construct your own home, and to have other user's visit, will be a great addition, but why stop there, along with many features from rs, we could potentially expand.. buy not just being able to build a simple house... but a castle?
Ofcourse, nothing too big, but starting off with a simple shack.. to a farm house... to a elegant home... to a royal castle, each home has it's own perks, for example, the castle will feature a throne room, trophy room, potential for a huge garden, and of course, butler service, while a simple shack will only have the basic rooms of a home, kitchen, bedroom, living room etc. Just like the other skills, add the chance for gear to build faster, and the pet.
Complete Mastery Capes - We have seen these before, but nonetheless a good addition, for completely maxing a skill (maxed xp) offer the player a cape, along with a title.
In-game / Forum Titles
Everyone loves to show off their achievements, I don't think it should be secluded to just in-game, When a player has mastered every skill, they should also be able to show off that title within the forums, if a player is a great pker, with many confirmed kills, they should also be able to show that off in the forums with a unique title.
Religion / Worship
This could be a great addition for the game, Giving us the ability to worship a certain god, in return granting us small perks, whether we stick to RS gods, or create entirely new ones would be down to everyone else but i shall give examples for RS gods, but as players will simply just swap god's to match what they are doing, it could be good to make them tasks, so you are unable to get the blessings from the god until you complete their task.
Bandos 'The God of War' - As the god of war, It would fit to see him provide us with combat perks.. giving us potentially extra damage against all other NPC's (can be obtained by defeating Graardor a certain amount of times)
Zaros 'The God of Fate & Control' - Potentially, Zaros could provide the blessing of luck, giving all users with the blessing a higher chance of receiving rare item's. (can be obtained by receiving a certain amount of rares)
Guthix 'The God of Balance' - Easy one here, definitely a skiller's god, providing skiller's with a chance of receiving double resources and/or bonus xp. (can be obtained by achieving a mastery in a non-combat skill)
If this is something people would like, we could always think of more.
Thought I would add a potential minigame for those more interesting in PVP, this idea is coming from games such as Smite, or LOL, where you choose roles, and are then only allowed to use the abilities of that role, so for example, we could have 4-5 roles, a mage, ranger, champion (tank), beserker (assassin) and hero (warrior), you then are allowed to either pick gear which will be spawned for you, or for high risk, bring your own, we could add objectives here, or just simple battles.
Again these are just simple suggestions and I would love to hear feedback, especially if you know ways of making these better.
Best I can do for now, I will either update this post or create new ones, depending on how long it takes for me to come up with more suggestions.