I. General Question: Suppose you have two or more chords slurred together. What are some different ways to get the slurred effect? The only two I know are:
There are generally a variety of ways. a) Use the pedal, as you said. b) use different fingers, as you said. c) if the passage is fast, simply playing the chords will give a legato effect. d) change fingers on one or more notes of a chord to prepare for the next chord.
(OK, and, if you wanted to apply this to Fur Elise you could look at m66-69, https://www.mfiles.co.uk/Scores/Fur-Elise.pdf). (Oh, and actually it happens with individual notes too in m. 14, LH plays 3 octaves of E slurred together...but no pedal marking ALTHOUGH THERE IS ONE RIGHT NEXT DOOR IN THE MEASURE BEFORE! Should I be holding this score over a hot lightbulb?? ??)
It looks like your edition has only the original pedal marks. Some editors add liberal pedaling to the score. The arpeggios need to be played with pedal. The trick is to decide how. Let's take a look at measure 3, for example. You can do one of the following:
1. pedal at the beginning of this measure (with the A) and repedal with the E|B at the beginning of the following measure.
2. pedal with the A at the beginning, release with the A at the end of that measure, hold the A across the barline and pedal with the E|B.
3. Most "correct", though, is probably to pedal with the A at the beginning, release the pedal with the A in the right hand (there is a rest in the left hand!), play legato across the barline (no pedal) and pedal again with the E|B.
At the beginning, go with option 1 (it's the easiest). When you become more comfortable, play around with the other options. Apply any one of those schemes in these arpeggiated sections throughout the piece. It depends a bit on the sound you prefer. It may also depend on the piano, i.e. how the sound decays and also on the speed with which you play this piece.
Concerning measures 66-69, pedal at the first beat of these and the following measures.
II. How do you know what to accent or stress? Can you never take a "breath" during a slur? Are slurs put in by the classical composers, or some guy who may or may not know what they are doing (and what else might he be sneaking in unbeknownst to Beethoven)? Do a set of triplets sound tripletty (I think I mean defined by a slight accent/heaviness at the start of each)? Do they sound tripletty even when they're slurred? (Fur E m m77-83)
This is a very complicated question whose answer depends, among other things, on the style of the piece, the type of the piece, the rhythm, personal interpretative choices, etc. I'll start with a couple of very general "rules": Take measure 80; do a slight crescendo to the top E, then a slight decrescendo back down. In other words, the highest note in a phrase often is played louder than the rest. One more: the last note in a phrase is usually soft. Start with a low wrist at the beginning of a phrase, end with a high wrist. This lifts off the hand from the keys and makes it easier to articulate the phrase. In many situations, there is a slight crescendo to the penultimate note, and the last note is played quite a bit softer. Finally, notes on the beat are usually more accented than those between beats. Notes on "strong" beats are accented (e.g., beats 1 and 3 in cut time), and notes on weak beats are not.
This is much less than the proverbial tip of the iceberg.