1.:

3N2r1/3Kp3/4Pk2/8/Bp6/6b1/2P5/8 b - - 0 1

Analysis by Houdini 2.0b Pro x641122:

1...Tg5 2.Lb3 Le5 3.Sc6 Ld6 4.Sxe7 Lxe7
  -/+  (-1.08)   Tiefe: 6/16   00:00:00  3kN
...
1...Txd8+
  -+  (-1.53 !)   Tiefe: 24/43   00:00:05  122mN, tb=609
...
1...Txd8+ 2.Kxd8 Kxe6 3.Ke8 Kd6 4.Kd8 e5 5.Le8 Kc5 6.Lh5 Kd4 7.Ld1 e4 8.Kd7 Kc3 9.Kc6 e3 10.Kc5 Ld6+ 11.Kd5 Kd2 12.Lg4 Kxc2 13.Kd4 Kd2 14.Kc4 e2 15.Lxe2 Kxe2 16.Kb3 Ke3 17.Kb2 Kd2 18.Kb3 Le7 19.Kb2 Ld6 20.Kb3
  -+  (-3.81)   Tiefe: 25/60   00:00:28  720mN, tb=5603

3N2r1/3Kp3/4Pk2/8/Bp6/6b1/2P5/8 b - - 0 1

Analysis by Zappa Mexico II555:

1...Tg4 2.Sc6 Ld6 3.Lb3 Tg1 4.Sa5 Td1 5.Kc6 Kf5 6.Ld5 Lf4
  -/+  (-0.95)   Tiefe: 14/27   00:00:01  3371kN, tb=3
...
1...Txd8+ 2.Kxd8 Kxe6 3.Ke8 Kd6 4.Kf7 e5 5.Kf6 e4 6.Kf5 Kd5 7.Lb5 Kd4 8.Le2 Ld6
  -/+  (-1.09)   Tiefe: 18/40   00:00:05  40919kN, tb=649
...
1...Txd8+ 2.Kxd8 Kxe6 3.Kc8 Kd6 4.Kb7 Kc5 5.Ka6 e5 6.Ka5 Le1 7.Lb3 e4 8.Ka4 Kd4 9.Lf7 Kc3 10.Lb3 Lg3 11.Kb5 e3 12.Lc4 Ld6 13.Kb6 Kxc4
  -+  (-3.03)   Tiefe: 25/43   00:00:38  340mN, tb=32623

2:

8/r3k3/1r1p2p1/2pR1p1p/2P1pP1P/pPK1P1P1/P7/1B6 b - - 0 1

Analysis by Deep Junior 11.2 UCI1553015:

1...Tab7 2.Td1 Ke6
  -+  (-2.03)   Tiefe: 6   00:00:00  1kN
...
1...Txb3+ 2.Kxb3 Tb7+ 3.Kc2
  -+  (-2.01)   Tiefe: 12   00:00:00  1892kN
...
1...Txb3+ 2.axb3 a2 3.Lxa2 Txa2 4.Td2 Ta1 5.Tg2 Ke6 6.Te2 Kd7 7.Tg2
  -+  (-1.82)   Tiefe: 27   00:00:24  552mN

8/r3k3/1r1p2p1/2pR1p1p/2P1pP1P/pPK1P1P1/P7/1B6 b - - 0 1

Analysis by Zappa Mexico II555:

1...Tb8 2.Lc2 Tab7 3.Ld1 Ke6 4.Td2 Tb6 5.Le2 Kd7 6.Ld1 Ke7 7.Td5 Ke6 8.Td2 Ke7
  -+  (-1.62)   Tiefe: 17/37   00:00:01  3510kN
...
1...Txb3+ 2.axb3 a2 3.Lxa2 Txa2 4.Td2 Ta1 5.Tg2 Kf7 6.Th2 Tg1 7.Kc2 Txg3 8.Kd2 Ke6 9.Th1 Ke7 10.Th2 Kd7 11.Th1 Ke6 12.Th2 Tg1 13.Kc3 Te1 14.Kd2
  -+  (-1.96)   Tiefe: 23/58   00:00:24  231mN
1...Txb3+ 2.axb3 a2 3.Lxa2 Txa2 4.Td2 Ta1 5.Tg2 Kf7 6.Th2 Tg1 7.Kc2 Txg3 8.Kd2 Ke6 9.Th1 Ke7 10.Th2 Kd7 11.Th1 Ke6 12.Th2 Tg1 13.Kc3 Te1 14.Kd2
  -+  (-1.96)   Tiefe: 23/58   00:00:27  254mN

3: (Die ist nicht gar so schlimm, daher Hutiwuti default )

7k/6rB/6P1/8/2p5/2B2q2/3P4/4K3 b - - 0 1

Analysis by Houdini 2.0c Pro x6414:

1...Dg2 2.Lxg7+ Kxg7 3.Kd1 De4 4.Kc1 De2 5.Kc2 Dd3+ 6.Kd1
  -+  (-7.39)   Tiefe: 6/15   00:00:00  2kN
...
1...Dxc3
  -+  (-7.60 !)   Tiefe: 26/40   00:00:01  17771kN, tb=1030
...
1...Dxc3 2.dxc3 Td7 3.Ke2 Td3 4.Ke1 Txc3 5.Kd1 Td3+ 6.Kc2 Td7 7.Kb2 Tc7 8.Kc3 Kg7 9.Kb2 c3+ 10.Kc2 Tc6 11.Kd3 c2 12.Lg8 c1D 13.Ld5 Tc3+ 14.Ke4 De3+ 15.Kf5 Tc5 16.Kg4 Txd5 17.Kh4 Kxg6 18.Kg4 Td4#
  -+  (-#18)   Tiefe: 26/59   00:00:05  103mN, tb=2388

4: Die typische Anti-engine-Aufgabe, eine Festung, da hilft vielleicht momentan wirklich nur die 50ZügeDistanz- Senkung von Houdini 2.0c, ich glaube, das hat Robert Hourdart auch schon im talkchess zu dieser Stellung gezeigt:

8/5pKN/5Pp1/5kP1/8/Bb6/8/7q b - - 0 1

Analysis by Houdini 2.0c Pro x6414:

1...Dd5 2.Lb2 Lc4 3.Lc1 Kg4 4.Le3
  -+  (-7.65)   Tiefe: 6/11   00:00:00  2kN
...
1...Dxh7+ 2.Kxh7 Kxg5 3.Lb4 Kxf6 4.Kh6 g5 5.Ld2 g4 6.Kh5 g3 7.Kg4 g2 8.Le3 Ke6 9.Kg3 Ld5 10.Lb6 Ke5 11.Lc7+ Kf5 12.Kf2 f6 13.Kg1 Kg4 14.Lh2 Kf3
  =/+  (-0.67)   Tiefe: 17/46   00:00:08  252mN
...
1...Dxh7+
  -/+  (-1.25 !)   Tiefe: 30/48   00:00:36  908mN, tb=10539
1...Dxh7+ 2.Kxh7 Kxg5 3.Lc5 Kh5 4.Kg7 g5 5.Lf2 g4 6.Le1 Kg5 7.Lg3 Ld5 8.Lf2 Kf4 9.Kh6 g3 10.Lb6 Kg4 11.Lc5 Le6 12.Ld4 Lc4 13.Lg1 Kf3 14.Kh5 Kg2 15.Le3 Kh1 16.Kg5 g2 17.Lf2 Ld5 18.Ld4 Lc6 19.Kf4 Le8 20.Ke5 Lb5 21.Kd6
  -/+  (-1.25)   Tiefe: 30/50   00:00:38  940mN, tb=13478

5: Können eigentlich schon so ziemlich alle ziemlich schnell auf guter hardware:

7k/6rp/5BpN/1r4P1/8/8/8/K7 b - - 0 1

Analysis by HIARCS 13.2 MPP0:

1...Tb3 2.Ka2 Tf3 3.Le5 Te3 4.Lf6 Te6 5.Ld4 Te4 6.Lf6 Tb4 7.Ka3 Tb8 8.Ka4 Tb1 9.Ka5 Tb3 10.Ka6 Tb4 11.Le5
  -+  (-5.82)   Tiefe: 18/31   00:00:00  1990kN, tb=538
...
1...Tf5
  -+  (-5.83)   Tiefe: 19/31   00:00:00  2922kN, tb=1410
...
1...Tf5 2.Ld4 Tf4 3.Lc3 Tc4 4.Lf6 Tc6 5.Le5 Te6 6.Lc3 Te2 7.Lf6 Tf2 8.Le5 Tg2 9.Lf6 Tc2 10.Kb1 Tf2 11.Le5 Tg2 12.Kc1 Te2 13.Lf6 Ta2 14.Kd1 Tg2 15.Ke1 Tc2 16.Kd1 Tf2 17.Ke1
  -+  (-5.83)   Tiefe: 24/36   00:00:05  14434kN, tb=10542

P.S. Das sind natürlich schon außer den beiden nicht ganz so schweren Aufgaben, wo Houdini und Hiarcs default spielen, auch lauter engines mit Parametertuning...