Precious is the mortal more than pure gold

Is there anger in the love song? 

Yes, and plenty of it. Under the generic domain of wrath there are 5 stems that could be glossed as anger in some translations.

• rage -- קצפ (qxp) 66 times in 62 vs. 
• anger --  אפ (ap) 415 times in 397 vs -- but of these only about half are glossed as anger. The stem also is used for a particle, indeed, and for the body part, nose. 
• burning -- חרה (krh) 146 times in 140 vs, used with אפ sometimes and sometimes without it but interpreted or glossed as if the stem for anger was present.
• fury  -- עבר (ybr) 734 times in 645 vs but of these many more are glossed as cross over. Only 40 or so are about fury.
• angry -- אנפ (anp) probably related to ap, 19 times in 19 vs.

I don't blame humans, let alone G-d for getting incensed at at the state of the world. 

For example, here's a statement against Babel - a whole chapter of the song, but I will only pick verses 9 to 13. They surround a verse that proclaims the mortal human is precious. Maybe that's why there is anger in the love song. 

Fury and fierce anger mark the bounds of these verses

9 Behold the day of Yahweh comes, vicious and furious and fierce anger, to set the land desolate. And sinners he will exterminate from it.
ט הנ֤ה יום־יהוה֙ ב֔א אכזר֥י ועבר֖ה וחר֣ון א֑ף לש֤ום הא֙רץ֙ לשמ֔ה וחטא֖יה ישמ֥יד ממֽנה	16 18		T hnh iom-ihvh ba aczri vybrh vkron af lwum harx lwmh vkTaih iwmid mmnh
10 For the stars of the heavens and their follies will not boast their light. The sun will be darkness in its going forth, and the moon will not illuminate its light.
י כֽי־כוכב֤י השמ֙ים֙ וכס֣יליה֔ם ל֥א יה֖לו אור֑ם חש֤ך הש֙מש֙ בצאת֔ו ויר֖ח לֽא־יג֥יה אורֽו	16 17		i ci-cocbi hwmiim ucsilihm la ihlu aorm kwç hwmw bxato virk la-igih aoro
11 And I will visit on the world its hurt, and on the wicked their iniquity, and I will eradicate the pride of the presumptuous, and the pride of the ruthless I will abase.
יא ופקדת֤י על־תבל֙ רע֔ה ועל־רשע֖ים עונ֑ם והשבתי֙ גא֣ון זד֔ים וגאו֥ת עריצ֖ים אשפֽיל	17 17		ia upqdti yl-tbl ryh vyl-rwyim yvonm vhwbti gaon zdim vgavvt yrixim awpil
12 Precious is the mortal more than pure gold, and the human than the finest gold of Ophir.
יב אוק֥יר אנ֖וש מפ֑ז ואד֖ם מכ֥תם אופֽיר	6 8		ib aoqir anow mpz vadm mctm aopir
13 Therefore I will make heavens shudder and will the earth quake from her place, in the fury of Yahweh of hosts and in the day of his fierce anger.
יג על־כן֙ שמ֣ים ארג֔יז ותרע֥ש הא֖רץ ממקומ֑ה בעברת֙ יהו֣ה צבא֔ות ובי֖ום חר֥ון אפֽו	15 14		ig yl-cn wmiim argiz vtryw harx mmqomh bybrt ihvh xbaot ubiom kron apo

Other translations render visit as punish. But a visit of G-d should not be seen as negative. There are real consequences of our action or inaction, of course. If you look at that root pqd, visit, you can see it has a variety of possible glosses. Other translations interpret it as punish. I never do. 

I can certainly allow that it may be painful to our self-image to be corrected by God, but we should welcome such a visitation, because we may actually grow from it. The same life-giving spirit that broods over chaos can also give us life and get us to put aside our presumption and pride.