yes...get those replaced with crown or Implant

Yes you need to replace your missing molars as soon as possible , because the adjacent teeth might migrate in the gap causing dental caries on proximal surface of them subsequently resulting in pain and pathologies. You can choose from various methods of replacement like Implants, fixed bridges or removable.

As a thumb rule the tooth which has been lost or extracted must be artificially replaced at the earliest You can opt for a fixed prosthesis such as a full ceramic or Zirconium which is the best If you don't replace there is every likelihood that the opposite tooth will move to that area of extracted site. The adjacent teeth will also shift and become loose Eventually there will be several other issues relating to food impaction , gum disease , inability to chew and digest etc

Yes you need to replace the missing teeth otherwise the existing teeth will get disturbed leading to more damage. You can think of implants or bridges.

Hello sir, the tooth removed is first molar that is essential for grinding food. The empty area can cause the upper tooth to come down .So the missing teeth should be replaced soon.

Yes near by tooth shift to the place n disturb d occlusion,better go for prosthetic replacement