Avoid Blackhat SEO, it may work in the short term, but very quickly you will either get blacklisted or a dribble of traffic. Build long term organic traffic through blogging commenting, article directory posting and guest blogging
Black Hat SEO is bad habit. It penalized your website. Your ranking in this technique move suddenly, But after some time you have lost your site ranking. maintain High PR we should submit website URL in quality Directory and Social Bookmarking site. Article submission is best technique for maintain high PR of website.
You can never hope for long time reaps from Black-Hat SEO as google think such practices as unfair.You can have short term achievements from Black Hat methods but totally try to avoid their long use.
To recover from penalities you need to take corrective measures and then go for a review from Google to be back on SERPs.
No,Black hat is bad for website, may be It penalized your website. so don’t use off page process. use white hat method and manually submission in off page.you will definitely got best rank.if your website got penalized then refresh your website and remove all bad links of your website through the webmaster.
The title of the thread is “How to maintain high PR of a website?” while the body is asking about “how to maintain high rank of my website?” Page Rank and Search Engine Ranking are different. Black hat seo can only give you fast but short-term results and with backlinks generator tools, I think your website will be in worst situation like de-indexing and penalize.