With the availabilty of information background searchs are almost instant today and if you have a issue in your past it will come right back.
The two things I would reccomend hiring a lawyer where the convictions where obtained and have the convictions vacated.
Next I would contract the consulate of both countries and ask the question about restriction on travel.
In general misdemeanor convictions will not affect your ability to travel internationally. There are some significant exceptions, Canada being one. The airlines do not check the databases available to law enforcement. They do check a database which lists people suspected of terrorism which doesn't apply to you. As for Hong Kong and Thailand you should check with the consulate nearest to you.