been planning to redesign my site but content is still the same, will this affect the current rankings? changing to another hosting company, will this also an impact to its ranking?
Changing hosting companies will have no effect as long as their isn't any downtime. If your content and url structure is staying the same, are you just redisigning the images?
The order of content can have an effect. If something is brought from the footer (unchanged) to above the fold may have a small effect. That can be counterbalanced by the fact that your conversion rates increase due to a better design. I would create your new design on a test server then post both to site reviews so you can get specific opinions before changing
it only effects if you change your present url or change all contents or change html site into complete flash site.
Just changes in look and feel shouldn't hurt your rankings at all, but changing the navigational structure by adding more pages to it or changing overall page structure can affect you in the short term.
I disagree with the change of hosting issue. If you're on a shared IP with a banned site... it will affect your rankings. FWIW
If your content is same then there is no effect on keywords ranking...Another hosting company also not an issue...
Not strictly true, one of the factors google uses is how fast the webpage loads, so if you are moving from a sluggish hosting providor to a faster one, then it could have a small impact, however I am being slightly pedantic in the grand scheme of things.