4. Buddhists and Taoists have religious practices wherein they separate themselves from worldly affairs and practice asceticism, can that achieve salvation?

Bible Reference:

“Why should the heathen say, Where is now their God? But our God is in the heavens: he has done whatever he has pleased. Their idols are silver and gold, the work of men’s hands. They have mouths, but they speak not: eyes have they, but they see not: They have ears, but they hear not: noses have they, but they smell not: They have hands, but they handle not: feet have they, but they walk not: neither speak they through their throat. They that make them are like to them; so is every one that trusts in them. O Israel, trust you in Jehovah: he is their help and their shield. O house of Aaron, trust in Jehovah: he is their help and their shield. You that fear Jehovah, trust in Jehovah: he is their help and their shield. Jehovah has been mindful of us: he will bless us; he will bless the house of Israel; he will bless the house of Aaron.

3. In my view, any of the religions teach mankind to be good. Does that mean that no matter which religion mankind follows, as long as they are sincere and commit no evil deeds they will achieve salvation?

The Answer from God’s Word:

     He who is incapable of creating the world will be incapable of bringing it to an end, whereas He who created the world will surely bring it to an end, and so if one is unable to bring the age to an end and is merely able to help man cultivate his mind, then he will surely not be God, and will surely not be the Lord of mankind. He will be incapable of doing such great work; there is only one who can carry out such work, and all that are unable to do this work are surely the enemies other than God. If they are cults, then they are incompatible with God, and if they are incompatible with God, then they are the enemies of God. All work is done by this one true God, and the entire universe is commanded by this one God.

from “Knowing the Three Stages of God’s Work Is the Path to Knowing God” in The Word Appears in the Flesh