Is there way to run BAMOE on Spring-boot as a micro-service, like JBPM Kie Server on spring-boot using kie-server-spring-boot-starter dependency

Is the Database Structure same like JBPM or any difference exists between

It depends on what BAMOE version you are asking about, and also on what use case you are dealing with (ie. DMOE or PAMOE).

For BAMOE 8, you can definitively use SpringBoot. For BAMOE 9, you will be able to use SpringBoot for DMOE use cases only starting with version 9.2. For PAMOE use cases, SpringBoot is on the roadmap for a later support. 

The DB structures are usually different for a SpringBoot usage, but the differences depend on which DB you are using. There are specific DDLs to use which show you the differences between the schemas and that are to be used to set up your DB.

Yes, for decisions (DMOE), but not process (PAMOE).  A Spring Boot runtime has been added to DMOE v9.2.0 (latest release) but the PAMOE v9.2.0 release is still only Quarkus.  You can generate a Spring Boot-based container image for a DMOE v9.2.0 project, however Quarkus is highly recommended as Kogito was built with Quarkus in mind.  Take a look at my Maven Archetype project, which generates different types of BAMOE projects, including a DMOE project based on either Quarkus or Spring Boot.