I think initially he thought British could only be removed by force, could i be correct in this assessment?
See,Bose got disillusioned by Congress and its policy long time ago.But like many Indians,he clearly disagreed about Congress' position of total support towards British Govt during World War.As an opportunist,any sane person would wind up another "Quit India",which would not only rattle spine of British Empire,but it eventually could force them to leave.But Gandhi didn't go for it.
What Bose did was what was exactly needed.A mass protest would subjugate British Raj to the demand of freedom in exchange of fighting their war,because British Empire was loosing its size exponentially day by day at that time.Its major loss of East Asia,Africa,Europe and imminent attack of Germany on Britain itself - there was no more perfect timing to declare independence in the first place.But soon,tide has turned after USA joined and Germany suffered loss in USSR.If Gandhi forced Britain,there could be independence as soon as 1940.But just like my chess skill,Congress blew it when they had an overwhelming advantage.
You can argue the timing of Quit India.If it was in 1939,British didn't have much of a choice.But in 1942,they had.Bose envisioned that Armed Struggle was only way(I disagree though.Had Gandhi not recall Non Cooperation Movement,we'd probably get it even before 1925),because he thought,you can't bargain from the position of weakness,rather we should bargain from position of our strength.Yes,it was true that he was not in a position to fight British War Machinery,but during that time,he could.But he wasted his time with Germany,and when eventually he attacked using Japan's help,Japan blundered.That attack was too weak,too slow.Had it been on 1940s,India's history would have been different.