These are my OPINIONS of your OPINIONS.
1. The riffs are not identical. I actually tabbed the riffs a few pages ago to show the differences. Refer to that post.
2. Again, the riffs are not identical. They are SIMILAR, but not IDENTICAL. My opinion is that you have trouble differentiating between these two words.
3. There is NO Tina Turner in CT. None. I don;t know the journey song, but if you can honestly hear Tina Turner in that song, you may need a few cotton swaps.
4. They have acknowledged they used the melody. It would show liziness if they didn't have other songs that could replace it. They used it to actually enhance the meaning of the song. There is a difference between pilfering and homage. Again though, I would hate to get into ANOTHER arguement with you regarding your interpretations of different words.
5. I will use my aforementioned points. There are similarities, hey Don't look Back in Anger has the same intro as Imagine, but it's still a great song. Because pieces of songs creep into other ones as INSPIRATION does not imply lack of CARE, CONSIDERATION, or ORIGINAL THOUGHT.
If you genuinely want to use these arguements, you are supporting the wrong band. They have always recycled their own sounds, themes and sometimes, yes, riffs (although not in NLOTH).
Oh, helpful link for you too...
Dictionary.com