The quick answer to both questions is yes. HOWEVER, there are risks involved with using primers meant for another purpose. Many have done so, but there are many things to consider and cautionary steps to be taken. The major difference in primers is the thickness of the cup. Pistol primers are thinner than rifle and not designed to withstand the same amount of impact of higher rifle pressures. Examples of what can happen are the primers can get punctured by the firing pin from the higher pressure rifle round. In gas operated rifles this can cause a malfunction, possibly a squib due to reduced gas thru the gas port. Allow excess pressure to the bolt and firing pin, erode the bolt face and firing pin. As well as creat a unsafe condition for yourself and firearm. Although it can be done... extreme caution is a must!!!! I would most definitely reduce the load for a start. As a beginning reloader, I would most definitely recommend that you do a hell of a lot of research on burn rates of your powders, pressures they produce in your particular loads with the bullets you intend to shoot. Otherwise I would advise against it. At least until you are far more familiar with the dynamics of all involved. There are several videos on the subject. 2 that come to mind are... Elvis Ammo and Johnnie's reloading bench. Both are vary experienced.
As far as dry tumbling... this can be done anytime. Even with loaded ammo. If they're really corroded, I would recommend wet tumbling.