1) The din malkos which the eidim receive for testifying on ben grusho or ben chalutzo, is that a Kiyum of Kaasher Zomam or not? The first Tosfos "Meidin Onu" seems to say it is a kiyum. but in the Gemoro it's mashma it's not: "She'ein Osin bohem din hazomo kol ikar"
2) Tosfos on daf 4: DH: "Verabonon" says that V'hitzdiku is only a giluy on Lo Sa'ane that even though there is no act, there is still malkos. Then tosfos continues to explain the gemoro's answers that Lo Sa'ane is the Azhoro for Ka'asher zomam which is the maskono.
But what do we do with V'hitzdiku is it still a giluy on Lo Sa'ane? Even though there is no malkos from there? Could we say now that V'hitzdiku is a giluy directly on Ka'asher zomam, or can we just say that V'hitzdiku is a din by itself which says that when we know the eidim are lying they get malkos, in which case they should get malkos when bo horug beraglov and it's clear that the eidim are lying.
1) Tosfos is referring to the requirement of "Edus she'Atah Yachol Lehazimah," which is learned out from "v'Darshu ha'Shoftim... va'Asisem Lo Ka'asher Zamam," (Devarim 19:19), which implies that we can only be sure the witnesses are telling the truth if the witnesses can be given a punishment corresponding to their plotting (see Rashi, Bava Kama 75b DH Heicha d'Amrei). In Tosfos first answer, he is suggesting that since Malkus is just as severe (or more severe) an ordeal as being a Ben Gerushah, the testimony is considered to be "Yachol Lehazimah."
The Gemara on 2a, on the other hand, is simply saying that the even if the punishment is as severe as the crime, it is not identical to the crime in any way.
2) The Gemara in Bava Kama 75b makes it clear that it would be appropriate to give the witnesses Malkus in a case of "Ba Harug b'Raglav" (as long as it is not Nitan l'Azharas Misas Beis Din), since the witnesses transgressed Lo Sa'aneh. It is clear that that the Malkus administered due to the Giluy of "v'Hitzdiku" is indeed for Lo Sa'aneh -- which is indeed why Ben Gerushah gets Malkus.
Tosfos does not mean to conclude that there is no Malkus for Lo Sa'aneh. There is Malkus for Lo Sa'aneh, but only one Malkus per case. Tosfos holds that there is no such thing as being given Malkus simply because "the Pasuk says so." Every Malkus must have a Lav associated with it, even the Malkus of "Ka'asher Zamam" or "v'Hitzdiku." Thus, in a case where witnesses testify that a person is Chayav Malkus and they are found Zomemim, the witnesses cannot be given two sets of Malkus (Ka'asher Zamam and Lo Sa'aneh), since the Lav of Lo Sa'aneh is behind the Malkus of Ka'asher Zamam as well, and cannot be used to give a second Malkus in the a single case of false testimony.
This is the key to answering Rebbi Akiva Eiger's question on the Gemara (in Gilyon ha'Shas), by the way (see Rashash and Acharonim). The Gemara is not asking whether there is Malkus for Lo Sa'aneh in general . There certainly is, as is evident from Ben Gerushah. It is asking what Derasha Lo Sa'aneh is already being used for in this particular case of testifying falsely that someone is Chayav Malkus, which prevents Lo Sa'aneh from being used to administer a second set of Malkus. (This is true according to all three explanations for the Gemara that we have presented in the Insights.)