As far as the Ortiz decline question goes, he certainly has been a good hitter for us this year, but he is definitely hitting a couple fewer singles/doubles/whatever, and showing a slight drop in walk rate, though K rates are pretty stable over the last three years, and if his BABIP is falling, then that means he is getting fewer base hits on those balls in play. Looking at that three-year trend, if he loses another 20 points of wRC+ then we have a DH who is a below average offensive player.
BABIP BA OBP SLG wOBA wRC+
2013 0.321 0.309 0.395 0.564 0.400 152
2014 0.256 0.263 0.355 0.517 0.369 135
2015 0.236 0.243 0.329 0.470 0.340 114
As for projections of hit types:
1B 2B
2013 90 38
2014 74 27
2015 45 17
Ortiz had 600 and 602 PAs in 2013/14, and so we will pace to that. He has had 386 this year, which means that he is 64% of the way to that mark (if you think he will blow past that mark you can argue that, but he hasn't had over 606 since 2009 or over 627 since 2007). That puts him on pace for 70 singles and 26 doubles, slight declines compared to the previous few years.
I'm not saying that he is toast now, or is guaranteed to be next year, but it isn't logical to attack people who do feel that way, the trend is in their favor regardless of whether Ortiz gets to 500 HRs this year or not. He isn't falling off a cliff, but he is sliding steadily down a slope, and Hanley might be a better DH as soon as next year, depending on who replaces him in the OF.
edit: formatting