You do not ever need to purchase cosmetics or keys, or can play OSRS gold with an Ironman to avoid it all. Though the EoC is really needed by higher level PvM Combat Mode is still an option. Like everyone I put off studying the combat system, but love it. It has been greatly improved from the execution which drove way. You're missing a great deal if all is from OldSchool players!
Two things in RS3 are "negative:" that the MTX focus, as well as the UI. MTX does impact daily life as much as you think, if you do not let it. You proceed, and receive your daily chests. You can spend money but there is no way to actually play RuneScape game. Where MTX becomes is in RS3's update schedule. We'll see it again in a few months, when this sub gets filled with MTX complaints again. RS3 drops content updates, with long dry spells between. These dry spells are full of MTX promotions and events, usually.
Easy to ignore, but when it seems like the only thing Jagex is doing is pumping out MTX content, it becomes frustrating. The UI is complex and elaborate... but easy to comprehend with enough time. This is just MMORPG syndrome: the UIs are always complex. RS3 is extremely different from OSRS's straightforward approach to matters: battle, skilling, and actions are very complex, along with the completely customizable UI reflects this. It may be daunting, but is a positive for the hardcore player.
As someone with no life and any friend, I don't know where I'd be without runescape to buy RuneScape Mobile gold. Not only is it a fantastic game with thousands and thousands of hours of content, but I have met some truely great friends on there. Somehow all my insecurities and worries evaporate on RuneScape game. The folks I meet have at least one common interest; the world of Gielenor. I'll never forget how good I felt as though one of my good friends went out of his way when he knew I was just a few mil off obtaining a noxious staff and he seen me 7m since he knew I'd been working so hard for it. I knew none of my friends would do this for me..