hi, some of my keywords with high volume are ranking on first page in canada, but in the states i am on 3rd pages first result. what factors are contributing this disparity. what can be done here in this case. is it because of my links and tld distribution or some server location thing. what should i do to rank better in the US? i have shared hosting server in singapore.

the reason i dont want to use h1 is because i can have only one h1, however if i use several h2s. is it gonna help me rank? bacause google likes h1 more than h2, is google gonna give more priority or same priority to h2., and if that priority is gonna be less, what will be the percentage of that lessness? for ex: h1 gets 90 score if my h1 is missing how much score my h2 will get out of hundred(i know there is no such metric but i am just wondering anyways)

HI, i have changed some h1 and h2 , changed and added paragraphs,fixed plagiarism,grammar and added some pics with alt text, I have just done it today, I am ranking on second page QUESTION-1 is it gonna affect my 2 months SEO efforts? QUESTION -2 Do I have to submit sitemap to google again? QUESTION-3 does changing content on the site frequently hurts SEO?

lately i have been thinking , when a  crawler visits an already visited site  or indexed site, whats the duration of its scanning?