We don't need a replacement for Stevie - his position is now redundant.
Yes, we do. You're talking about positions and tactics, not the size of the squad. As he has declined, we've lost an arguably world class midfielder. Just like we lost Xabi and Masch. I want to have Emre Can's babies as much as the next easily impressed Liverpool fan. I think Jordan Henderson may become the stalwart leader half of us see in him. And I have nothing but love for Lucas. But even with Joe Allen, possibly Jordan Rossiter, and our wealth of attacking midfield talent, I still believe we need one more top class midfielder and I would rather see us spend big there than anywhere else.
Your approach is a bit shopping listy for me.
We need :-
1. a new high class DM (keep Lucas as backup),
Which would be the replacement for Steven Gerrard in terms of squad size and payroll, if that's the direction the club decide to go. Alternatively, we recognise that Lucas is the one and we start to groom a replacement for him. Or we use Emre Can in that position. Or Joe Allen. Or we reject the need for a purpose built shield for three centre backs and focus on controlling the ball and the game. Or any combination of the above.
2. another CB (bring back Ilori perhaps - his technical skills and great pace may be perfect for our Back Three) or 2xCB if we let Kolo go (personally I'd keep him for another year for his experience and the help he gives to the younger players). We need 5 CBs and fewer FBs with this system so Johnson, Manquillo, Wisdom and Enrique are all surplus to requirements. Flanno / Can / Toure can all play RB/LB if we ever revert to 4-x-x for any match.
I'm not convinced we'll continue to play 3-4-3. It's a model we were forced into by Sturridge's injury and the transfer failures last summer. However, I've assumed Ilori and Wisdom - who is naturally a centre back - will be back but yes, we may need a new one if we stick with this formation and they're not up to the job. However, that's one of the positions I reckon we should be buying potential for while we ask the manager to earn his money by making Sakho, Skrtel, and Lovren work as our first choice back line.
3. a replacement for Jones (Ryan is growing on me now I know he's not a midget)
A replacement for our backup keeper is not a major purchase and won't have an untoward affect upon the team or playing style. We either buy potential with time to grow into the role or an older hand not expecting to play every week. The much bigger question is whether we bring in a direct replacement for Mignolet. It would be good to have a Clemence/Grobbelaar situation for a season but I don't think it'll work out that way.
4. and a new striker (to replace Balo who it seems is nailed on to leave, Origi replaces Borini), Ojo, Ibe & Sinclair could/should see game time up front as well.
I'm not sure Borini will ever leave. And no one knows what will happen with Mario. Personally, I want him to stay but I can see a lot of other people want rid. In the whole recent penalty farce, no one seemed to want to acknowledge that Jordan Henderson is actually two months older than Mario. He has so much potential - and he's been turning in decent performances lately - that I'd love to see us persevere with him. Although if Icardi was available ...
My main idea here, btw, is that when we lost Suarez, we were forced into a redesign of the team and the raft of new purchases took time to bed in and we struggled to find our form and a way of playing. We don't want to make the same mistakes again. We need a season where we hit the ground running and consolidate our position as a top four side. The current squad is good enough to do that with the addition of a couple of high quality players in the right positions. Or so I delude myself.