So those fancy sounding ones as well as so called whitening toothpastes arent really good then?

Yeah most of the whitening toothpastes contains micro abrasive, so with repeated long term usage and improper brushing techniques it will start wearing down the teeth and causing them to thin out.

Just stick to the basic only white paste toothpaste will be good enough 😊

What matters is proper brushing techniques supplemented by flossing and a regular dental check up at least once a year.

I have unbalanced lower incisors, meaning 1 or 2 incisor is slightly behind the other incisors, like roof tiles overlapping a bit to the next tile. A toothbrush is too broad to properly brush the surface that is stacked behind another incisor. Thus incisors become stained and too eager brushing of the submerged incisor causes more abrasion to the incisor on front.Any solutions?

long term solution is orthodontics to align your teeth.

If not. you can get toothbrushes with slim bristles and angulate them to try to reach those tight spots. also regular flossing to clean those tight surfaces

If u pull out a tooth & do not replace them with denture or implant - the opposite teeth will grow longer? Is this true? How long will it take & is there any other way?

Is it too old to get braces when you are already above 30?

No.

its true, your opposite teeth will grow out to find something to bite with and neighbouring teeth may drift into that empty space.

Usually the most drastic change will happen within a year after you extract the tooth.

Alternative? dont extract the tooth! try to perform treatment to prolong the life of the tooth. or you have to consider and plan for replacement if its going to be extracted.