1) I had worked more than 8 months in the company - which would provide me strong ties
Merely being employed does not equate to having strong ties.
Your employment would be considered as a strong reason to return if your co-workers cannot do the work you do..... and/or if you have specialized skills..... and/or if you must return for some critical work commitment.... and/or if you earn above average salary levels.
2) I will make sure that I will add my dad's bank statements + his income tax returns + a letter of financial support + copies of any financial investments which can be liquidated,
Maybe you should prove that you can afford the visit with your own finances. That would give you significantly higher chances of a TRV approval as compared to applying as a financial dependent on your dad (despite the fact that you are employed).
How many years of VISA will I get ? ( 10 years multiple entry or until my passport expiry)
You're getting ahead of yourself. A TRV approval will depend on a number of factors: Purpose and length of visit + your individual strong ties to your home country + your financial situation + your previous travel history, etc.
Based on the assessment, the visa officer will determine whether or not a TRV should be granted + the validity of the TRV