Insignia™ 48" Class NS-48D420NA16 LED HDTV: This TV delivers Full HD picture quality in an uncomplicated, minimalist design. Easily connect a Blu-ray player, DVD player or gaming console. 
A: Yes
Q: can you connect to a ruku with this TV
A: Absolutely. I am using an HDMI cable to connect my Roku. The Roku is a must since I do not have cable but the OTA stations are amazing in HD.
Q: If I have 45 inches to fill in an Armour, what is the estimated max size TV is need?
A: The TV's dimension with the stand attached are 42.6× 26.8 × 9.7 in
A: Yes, it does have a digital tuner.
A: No it doesn't
Q: How far apart are the stand legs?
A: The legs on this unit are 34.5 inches apart at the widest point.
Q: How far apart are the legs on this tv?
A: You will need at least 40" wide and 12" deep for this TV to be safe and secure.
A: On the antenna, it will show current program content. I don't think it will show next program info.