How to place all the SPFx webparts to be appeared in same toolbox folder? How to change the SPFx webpart title?

 Ans:-

Answers for these questions reside in the webpart manifest file which is in the below location to do the settings for that

/src/webparts/{webpartname}/{WebPartName}WebPart.manifest.json 

"preconfiguredEntries": [{  

    "groupId": "5c03119e-3074-46fd-976b-c60198311f70", // Other  

    "group": { "default": "Other" },  

    "title": { "default": "First-SPFx" },  

    "description": { "default": "First-SPFx description" },  

    "officeFabricIconFontName": "Page",  

    "properties": {  

      "description": "First-SPFx Properties"  

    }  

  }]

If you maintain the same group id and same group name in all your apps, you will be able to see all SPFx webapps under one folder.