настоящей доверенностью уполномочивает
обоих вместе и каждого по отдельности,
представлять интересы Общества во всех ...
для чего предоставляю право заключать с компетентными органами от имени Общества договоры купли-продажи, аренды земельных участков и объектов недвижимого имущества, и любые иные не запрещенные законом договоры и соглашения, согласовывать их существенные условия, подписывать договоры купли-продажи, аренды и прочие договоры и соглашения от имени Общества, зарегистрировать договоры, права Общества и их обременения в Управлениях Федеральной службы государственной регистрации, кадастра и картографии (Росреестра) по Новгородской, Ленинградской областям и городу Санкт-Петербургу, и их территориальных отделах и подразделениях,
подавать от имени Общества все необходимые заявления, справки и документы, производить необходимые согласования с компетентными органами, службами и организациями, производить межевание и геодезическую (инструментальную) съемку земельных участков, согласовывать их границы на местности, вести межевые дела, принимать участие в аукционах по продаже земельных участков и иных объектов недвижимости и прав аренды земельных участков и иных объектов недвижимости, уплачивать покупную цену за земельные участки, объекты недвижимости или за права

hereby authorizes:
both of them together and each of them individually,
to represent the interests of the Company in ...

for which I grant the right to conclude contracts with the competent authorities on behalf of the Company for the sale and purchase of land and real estate, and any other contracts and agreements not prohibited by law, to agree on their essential terms, to sign contracts of sale and purchase, lease contracts and other contracts and agreements on behalf of the Company, to register contracts, the rights of the Company and their encumbrances in the Department of the Federal Service for State Registration, Cadastral Records and Cartography (Rosreestr) for Novgorod region, Leningrad region and Saint-Petersburg, and their territorial divisions and subdivisions,
to submit all necessary applications, certificates and documents on behalf of the Company, to execute the necessary approvals with the competent authorities, services and organizations, to execute land surveying and geodetic (instrumental) surveying of plots of land, to coordinate their territorial boundaries, to conduct land surveying, to participate in auctions of sale of land plots and other real estate and lease rights of land and other real estate, to pay the purchase price for plots of land, real estate or for land leasehold, real estate objects, to accept land plots and real estate objects under the acceptance and transfer acts, to sign all the necessary documents accompanying the purchase and acceptance of land plots and real estate objects, including protocols, contracts, acts, agreements, agreements on amendments, attachment and termination of previously concluded contracts, etc.

They're required, to make clear the link between the initial 'I grant the right' and each of the activities listed – to make the text unambiguous, which is particularly important in long sentences and in legal texts. So it's like a bulleted list which says:

I grant the right:
* to conclude contracts ....
* to agree on ....
* to sign contracts ....
* to submit ....
* to execute ....
etc.

Also, a lot of infinitives in English can be mistaken for nouns if you remove the 'to' from them (to sign, to register, to conduct, to pay). Retaining the 'to' makes it clear that they're verbs.

м.б. заменить на "addenda"?
http://definitions.uslegal.com/a/addendum/