We need a mentality change more than players in my mind. That being said, my wish list in order of importance would be:
1. A striker that can reliably deliver 15+ goals. Tosun has looked ok, but we need competition/injury cover. We never replaced Lukaku.
2. A commanding CB (I don't think that Keane has the mentality at all)
3. A box-to-box midfielder who can sit and spray a good pass most of the time (to compliment Gana)
4. Another winger to replace Bolasie...someone who actually likes to stay wide some of the time
We should trim the squad in midfield and put Siggy/Vlasic as #10's and ditch Rooney (he has been ok, but we need to be getting Siggy where he should be).
Agree on the needs, but I would personally reverse your list completely:
1. Winger- Take a look at what Walcott has provided since coming in, it has been immense, we are sorely lacking that ability on the other wing and imo is the biggest glaring hole in the squad, and it's affected Baines' ability to get forward as well.
2. Midfield- since Barry left it has been dreadful, Schneiderlin a huge disappointment. Davies wants to play up the pitch too much to fill this role and Beni isn't ready for a full time load.
3. CB- Keane, Funes Mori, and Holgate are a nice group but agreed on a more commanding CB.
4. Striker- Tosun looks to me like he can finish if given decent service, competition/backup is a luxury imo compared to the other needs, Niasse can put a shift in off the bench and I still like DCL.
I agree on Rooney, it feels weird for a team lacking in goals to want to ditch their top scorer but as long as he's here he'll be played- can't see him being happy off the bench regularly.
But the biggest need that doesn't even need to be mentioned is a quality manager with ambition, backing, and a plan.