Can ideal tsh vary from person to person? ie., can some one with tsh of 4.0 feel miserable for an individual but not another? sub clinical hypo?

Yes: Many of us feel that the "normal" value of TSH is more toward 3.0 rather than 4.0. That being said most people with subclinical hypothyroidism with normal T4 and TSH 0f 4-10 have few symptoms. Your doctor should look for another cause for feeling miserable before starting thyroid replacement.

Yes: Depending on the labs and the test, the 'normal' range of TSH can be from .5 to 4.5 or so. Symptoms may occur at 4.0. Some endocrinologists will treat at 3.5. Have you had your T3 (liothyronine) and T4 checked? Thyroid antibodies checked?