How to create projects in Tilemill Ubuntu Web service?

I have set up Tilemill on a Ubuntu server and successfully accessed it from browser using

TILEMILL_HOST:20009

I have already uploaded planet_osm data to postgresql/PostGIS DB in the same server machine. At first I have created a "Test" project where I have added a layer using the following information but the tiles were broken.

dbname=osm 
host=<PG_DB_HOST>
port=<PG_DB_PORT>
user=<PG_USERNAME>
password=<PG_PASSWORD>

For the Subquery for testing pupose I used the following query

( SELECT way, name, amenity FROM planet_osm_point
WHERE amenity IS NOT NULL AND name IS NOT NULL
) AS data

Unfortunately there is no visualization in the web browser.

Basically I have created a custom design for an area in my local machine. I want to export MBTiles file to the server directly. I am using Tilemill for Windows locally where I have created that custom project. Now I want to transfer the MML project files and MSS Carto CSS files to the server and export MBTiles. The map changes will be frequent, this is why I need a solution where I can only upload the MSS and MML files to server and export MBTiles from Command line. The Local DB and Server DB Schema is similar. Now I have the following difficulties-

1. How to setup the project?


2. How to establish connection to PostGIS through Tilemill web service?


3. How to upload MML project file, MSS cart CSS files and other shapefiles and icons to server and which directory to upload?


4. How to export MBTiles? (Though I have read this Article. I am mentioning this question if there is any changes in exporting command while using Tilemill as web service)