Gameplay is choppy at times, but I have enough CPU power? Although the FPS counter shows 100% speed for these games, they may appear choppy. This is true to the original — even the original hardware of these games struggled with them and therefore the choppiness is actually accurate emulation of these games. You may be able to get rid of it in some cases by using the -cheat parameter, hitting the tilde key and browsing the on screen menu until you find "CPU overclocking". This will run the emulated CPU faster which may or may not fix it. It may also cause the emulation to have errors, so don't bug people if overclocking screws up a game.
How to activate Blood? Hit F2, use the player 1 controls to navigate to "Setting up the soft dip", hit the primary button (Left Control), navigate to "Slot 1 (game name)", hit the primary button and finally navigate to the "Blood" selection and turn it on by hitting the primary button. To exit the menu, press the third button (Space) two times and select "Exit".