Interesting TL,but the part about the IRA[or more historically accurate the IRB] is totally ASB. Even with German support[rifles,machine-guns etc] the IRB would not have a hope in hell of inflicting a defeat on a British formation in open combat. They were a guerrilla army,striking through ambushes and could never go one-on-one with the British army no matter how well supplied. The IRB also depended greatly on the support of the local population[as seen in the war of independance] for safehouses,supply dumps and info on British troop movements. So,the idea that the IRB could somehow march through hostile unionist controlled Ulster,keep a functioning logistical system,avoid the UVF and inflict a decisive defeat on the British army at the gates of Belfast in 1916-is totally impossible. And even if ASBs were giving them a boost through out the campaign[think:a few meteors falling on British bases] the British would still never give up Ireland because they considered it vital to their national security,which now be even more of an issue since their defeat by Germany[not to mention British fears about Irish discrimination against Protestants,RN access to irish ports etc].