Is is true achievements safe to sign my Microsoft account in to

Yes, True Achievements is safe.

If you enter the E-Mail Adress, Phone Number or Skype name of an already exisitng Microsoft Account, it will prompt you to login with your password.
You'll only get prompted to create a new Account, if you enter data without an associated Microsoft Account.
Your Purchased Games, Save Data, Achievements etc. are all safely stored on your Microsoft Account. They are available to you after signing in.

How do i check my progress on true achievements website for jump force just getting warmed up achievement

Sign up for an account with your tag. Once toy are signed in there is an icon in the top right corner next to your gamertag to force scan your account. You can do that a limited amount of times per day with a free account (unlimited with pro). That will
bring your recent achievements on site and you can drill into the game you want to see your progress in.

Not that I've seen unless you go to your achievements page and hardcore look around. If you go to the website True Achievements or download their app on the Xbox One you can check your total lifetime achievements and a bunch of other history stuff
like potential on there. All you need to do is sign in with your Microsoft account. If you download the Xbox app it even adds a widget on all achievement screens to let you search for it on the app.

I don't think TA gives you an easy way to calculate totals, plus they mess up numbers with their "true achievement" number as well.

Not that I've seen unless you go to your achievements page and hardcore look around. If you go to the website True Achievements or download their app on the Xbox One you can check your total lifetime achievements and a bunch of other history stuff like
potential on there. All you need to do is sign in with your Microsoft account. If you download the Xbox app it even adds a widget on all achievement screens to let you search for it on the app.