Is it possible to directly update SQL tables using Tm1? If yes, what steps do I have to follow?

Attached is the new version of a little parser in perl (free) that will create a text file for graphviz (free too) out of your .pro and .rux files and then generate a graph of the data flow in your TM1 server...

if you ever loaded a .sub file (subset) in an editor this is the format you would expect:

283,2 start
11,yyyymmddhhmmss creation date
274,"string" name of the alias to display

Homemade TM1 reports can get quite convoluted and users might get a hard time updating them as it is difficult to tell where some TM1 formulas are pointing to.
The excel formula auditing toolbar can be useful in such situations.

TM1 processes will not complain when their input source is empty.
So although the "process successful" or "chore successful" message will popup, your cube will remain desperately empty.
In order to solve that "silent" bug (or Cogglix feature), you will need to add specific code to your TI processes to test against empty sources.