You still have one of those weird transition teams that would be pretty on point in a few years if you let it grow organically, like Arsenal did after Fabregas, Nasri, Song and RVP left.
You could do with a CB regardless as Skrtel needs to be replaced. Lovren there is still a possibility that he can make it in the team as a first choice. Koscielny was trash for a good few years and he's one of the best defenders in Europe now, Lovren requires some patience I feel but the time is up for Skrtel. Sakho is not reliable enough due to his injury problems, might be an Agger situation, hopefully that is not the case.
Can, Henderson, Coutinho, Firmino definitely have a future in the first team, Sturridge and Benteke do too. You could really build a team around all of these players, adding quality bit by bit. Also it's yet to be seen if Ings and Origi can have a realistic consistent impact on the team over a period of time. You could probably do with a Gotze signing as a signing of intent, like Arsenal did with Ozil back in 2013. He's just one of those players that you buy if they're available and you can afford it.