So first things first I am well aware I should just be developing my stadium until I get to full execs and vips and mostly have stuck to that and will take another big step toward it in my bye weeks coming up.

I have also been trying to eradicate all non 3.5* talent from my team and only have 3 players left who are not in that threshold (rb, and two cb's).

I did this mainly because it bugs me developing players who cant get to 4.5 star overall bpos so I have probably overspent on that but now I find myself wondering should I now aim for 4.5 star talent (bearing in mind i'm still building up my stadium)because now it bugs me that I have a lot of players who wont be able to hit 5 stars bpos.

Is it just a case of gradually building it up or is it now a game of consistently looking for the right level of talent?

I've got 33 players with either 4.5 or 5.0 talent. It didn't take me that long to collect these, although I may just be lucky. I found when i'd finished building seats I had plenty of free cash to go on the recruitment trail. I spent this money buying 3.5*+ talent initially but then, as you mention, decided it would bug me not having the maximum available. I'm now having to balance having a competitive team with giving my 5* players the games to earn their BPOS which is annoying so i'd be tempted to switch to only settling for 4.5*+. Having said that the new engine may make this an irrelevance. Who knows!