Guys lets not get to emotional here. I think we can't call this book as nationalist inspired.

Trust me Portner is far from nationalist. He dosen't present historiography like that  Thow its true he isn't linguist and most of his book dosen't deal with such things rather pure historiography without any pomp additions. Indeed Porter belongs to that line of historians who compleatly broke with romantic portraying. At any rate he probably meant word ruotsi steems from germanic scandinavian word for oarsmen, which actually it dose but maybe presented this a bit errorous. Its like one line dwarfed with over 300 pages of detailed information on expansion of "viking" groups.

Again i stress he isn't linguist and linguistic questions are left open by him. There are always some errors even among top historians after all.

As far as genetic goes i won't say much thow tbh. i personally believe genetics can't mach linguistics by default. However the word is supposed to mean anyone from Scandinavia irrespective of linguistic branch but lets be honest most archeological, linguistic and historiographical data dose point bulk of people under term Rus who came to these east lands and passed the name to locals were speaking germanic tounge.

Personally i never heard Slavs use such word for Scandinavians, thought an input of Baltic Slavs as Poles, Belarussians or Russian would be valuable here…i highly doubt they use (or used anything similar) for Scandinavians as well, rather just used it for the specific Rus tribe which the author then in turn generalizes upon all Scandinavian or even Germanic tribes. 

Ofc. not. Its meant that in those early times Slavs called Scandinavian people like that. Later the name transfered to Slavic groups that were under political domination by these peoples.

Quite true, I read something about that topic yesterday aswell and I was disgusted about how the book claimed mostly everything about early Kievan Rus', knez Vladimir, Igor, Novgorod and more to be based purely on Swedish Vikings.

Well this book is quite clear that the Scandinavian groups which came there were traders and merchants who soon blended and were gradually assimilated into local areas.