If God wills that all men be saved eternally, which he doesn't,
3 For this is good and acceptable in the sight of God our Savior, 4 who desires all men to be saved and to come to the knowledge of the truth. (1 Timothy 2:3-4)
As it says, He desires all men to be saved and to come to the knowledge of the truth.
9 The Lord is not slack concerning His promise, as some count slackness, but is longsuffering toward us, not willing that any should perish but that all should come to repentance. (2 Peter 3:9)
He is not willing that any should perish but that all should come to repentance.
He would save them.
5 Trust in the Lord with all your heart, And lean not on your own understanding; (Proverbs 3:5)
Nonetheless, your understanding is insufficient, because His ways are not our ways, nor are His thoughts our thoughts (Isaiah 55:8-9): His judgments are unsearchable and His ways are past finding out (Romans 11:33).
8 "For My thoughts are not your thoughts, Nor are your ways My ways," says the Lord. 9 "For as the heavens are higher than the earth, So are My ways higher than your ways, And My thoughts than your thoughts. (Isaiah 55:8-9)
33 Oh, the depth of the riches both of the wisdom and knowledge of God! How unsearchable are His judgments and His ways past finding out! (Romans 11:33)
So, although He longs for everyone to be saved, He still chooses not to save them, according to the purpose of Him who works all things according to the counsel of His will (Ephesians 1:11), that His purpose according to election might stand (Romans 9:11).
Dan 4:35, And all the inhabitants of the earth are reputed as nothing; and he "doeth according to his will" in the army of heaven and among the inhabitants of the earth' and none can stay his hand, or say uwnto him, What doest thou?
Although He is not willing that any should perish, He also wills that many (Matthew 7:13-14) should perish, and this latter will supercedes the former. We know this because, although He wills both, He chooses to cause only the latter. Therefore, He does according to His will among the inhabitants of the earth (Daniel 4:35).
Isa 50:2, Is my hand shortened at all, that it cannot redeem? or have I no power to deliver?
He can redeem, and has power to deliver; He simply chooses not to. See above.
Mark 16:16, Pay particular attention as to what salvation he is talking about, it is not eternal salvation, but baptism saves (delivers) us from a guilty conscience, 1 Pet 3:21.