1- I'm trying to check for a manual on how to use the platform. It seems I cannot find anything beside the manual provided officially on the site- I believe this question was asked before and the answer was negative
No, no other manual than included user manual.
Think of F1 key on a screen : it will open manual at corresponding page
Also on manual, click on PROJEQTOR icon on top left will open table on content : there have a look at "concepts"
2- I have a project usually, which have deliverables linked to certain milestones. Every project has different deliverables and different milestones. Each milestone has a weight to keep track of progress.
My main concern is to track progress on a given date based on the date of completeness of each milestones of each deliverable. Is this possible in Projeqtor?
A milestone cannot have a weight : it has no duration and no workload. DEliverable can have weight, but it does not give progress of project.
Progress of project os work driven : activities give progress, and their weight is the assigned work.
3- Is there anywhere in the platform where I can upload already existent excel sheet that has projects details, dates, milestones and deliverables and proceed with the progress tracking from Projeqtor?
You can upload items through import feature.
But you'll have to import by item types : projects, then activities, then milestones.
4- Is there any possibility to customize reports and charts produced?
Not as of today, not without coding.