Great Information on the history of Tang Soo Do!

Regarding the style's Chinese heritage, may I ask if anyone has information on this:

1. Is the Sip Sam Sui form of Tang Soo Do really a kung fu form as stated by the Moo Duk Kwan Organization?

2. Is the Tae Keuk Kwon Form the same as the Tai Chi long form?

3. Is the So Rim Jang Kwon form the exact same form as that practiced by the Northern Shaolin Chang Quan?

4. Are there any websites that contain more detailed movements on these forms? Are they purely Chinese or are they Koreanized versions?

Thank you.