Let us not forget Islam spread itself solely by vicious conquest.

The Arab armies spread by conquest. Islam was largely spread by taxation. Countries like Egypt and Persia gradually converted over hundreds of years as preferable tax rates and political positions were afforded to Muslims.

In Southeast Asia, Islam was spread solely by traders.

Hispania was under Islamic oppression

The Umayyads, who ruled over Spain, were arguably the most enlightened Muslim dynasty. They were also disconnected from the Abbasids and the Turks - who were the primary threat the Byzantines.

300 years earlier.

Right. hundreds of years earlier.

They were invading the Holy lands to protect pilgrims and retake them from the Muslims.

Considering the widespread massacres of indigenous Christians and Jews, I doubt they were particularly concerned with their welfare. They were religious fanatics funneled into the East by the Byzantines.

If we are to condemn the crusaders for that we should at the same time mention all the Islamic massacres that preceded the crusades.

I'm not sure I understand your point. Does that mean that we have to denounce decades of terrible foreign policy before we condemn ISIS's atrocities?

No one alive at the time of the Crusades ever remembered a time when the East was Christian. Considering the fact that the Crusaders would later go on to sack Constantinople, one of the greatest Christian cities in history, I think it's safe to say that they weren't exactly holy warriors.

I'd recommend you have a look at /r/AskHistorians. They have some very informative posts about that period of history.